Newbee Loading question

[holdover]

I have a box of 77 gr HPBT sierra match kings .

I cannot find it in my reloading books.

Sierra website says :


.22 CALIBER 77 GR. HPBT MATCHKING

Designed for Service Rifle competition in the M16A2/AR-15A2, our 22 caliber bullets have set an incredible number of new national records. The 77 grain #9377 MatchKing® allows seating to an OAL that permits cartridges to be loaded into M16/AR15 magazines.

But I cant find the over all length for the loaded cartridge .or the proper loading data .

Is there an online site to find the load?

Where can I find the trajectory data for determining drop rates ?

I have the tenth edition Hornady reloading book , Lee book , and another book .

 

[kev74]

Find a recepie for another 77 grain bullet, then start with the start load and work your way up.

 

[holdover]

My manuals dont have it listed. they have 80 and 75 gr

 

[holdover]

My Hornady book has 75 gr Amax COL 2.390
75 hpbt col 2.250
75 eld match col 2.390

would those numbers fit my Ar mag?

 

[holdover]

Take Aim at Rifle Reloading Data | Hodgdon Reloading

 

[kev74]

I usually start out with the longest OAL I can that still fits in the magazine. You should be able to be well over minimum OAL and still fit the magazines.

 

[holdover]

Have any references?

 

[Mosinitis]

They are designed to be loaded to magazine length (unlike Sierra 80gr). I shoot a lot of them. I will find some data on them and post.

 

[Mosinitis]

Couldn't post this link from my tablet, had to use a laptop.
This is from Sierra loading manual. Read the first page and scroll down to 77gr HPBT

http://accurateshooter.net/Downloads/sierra223ar.pdf

 

[JamieZ]

77gr Sierra bullet OAL is 2.260,,,which will fit in a AR mag. The website you posted has it listed.

You cant determine drop rate until you come up with an accurate load that you are able to measure velocity.

Come up with an accurate load, measure velocity average after firing a few rounds and then download Srelok Pro on your phone for 12 bucks. Punch in the info for the rifle you are using, punch in the info for the bullet that you ended up loading after you did your accuracy test and velocity test. Punch in the info for the scope you are using. Once this shit is done Strelok Pro will give you everything you want to know.

 

[Mosinitis]

He doesn't have ransom rest to test for accuracy load. Also, unless he is a top notch benchrest shooter, he doesn't have the skill to benefit from accuracy load. It's very easy to load for 223. Pick a powder and work up a load that doesn't give pressure signs. Ballistic advantage (speed) and temperature stability outweigh accuracy load, which by the way changes over the life of a barrel. I have two walls full of shooting medals and awards and I never bothered to develope an accuracy load.

 

[JamieZ]

He doesn't have ransom rest to test for accuracy load. Also, unless he is a top notch benchrest shooter, he doesn't have the skill to benefit from accuracy load. It's very easy to load for 223. Pick a powder and work up a load that doesn't give pressure signs. Ballistic advantage (speed) and temperature stability outweigh accuracy load, which by the way changes over the life of a barrel. I have two walls full of shooting medals and awards and I never bothered to develope an accuracy load.

Guess I made a mistake. When I say accuracy load Im speaking of testing out different loads of powder to find a load that shoots accurate and you dont get pressure signs. What the hell do I know but thats how I test out all my loads before I load a shit ton of them.

Just figured if you are reloading that you would want an accurate load and not a fucked up one that is just fast.

My shooting is strictly for hunting and when I load I want to start out with an accurate round before I go any further loading more.

I know one thing,,,,,,,,he doesnt hunt and shoots targets only,,,,,,,,,,,so maybe he does want an accurate load.

 

[Mosinitis]

Guess I made a mistake. When I say accuracy load Im speaking of testing out different loads of powder to find a load that shoots accurate and you dont get pressure signs. What the hell do I know but thats how I test out all my loads before I load a shit ton of them.

Just figured if you are reloading that you would want an accurate load and not a fucked up one that is just fast.

My shooting is strictly for hunting and when I load I want to start out with an accurate round before I go any further loading more.

I know one thing,,,,,,,,he doesnt hunt and shoots targets only,,,,,,,,,,,so maybe he does want an accurate load.

Sierras 77's are very accurate bullets. All loads suggested in Sierra manual are capable of sub-MOA groups. Accuracy differences will be too small to see when shot side by side and will be lost in much bigger factors like shooters skill and wind conditions.

 

[Robin]

When zeroing a muzzleloader first you get the sights in alignment so there is a grouping on the target, located on or near the bulls eye. Then the fun begins as different amounts of powder are tried, differing thickness patching, even different diameter balls, all done methodically of course. When you are on the right track you can see the size of the group shrink until you find that combination your barrel likes and one big ragged hole is achieved. After that some minor tweaking of the sights will put you right on target.
That is the same attitude of methodology I use when working up a load for my center guns. Mosin may think its all a waste of time and that's okay, but at the end of the day I can be confident that when I miss, it's me, not my equipment.
Robin

 

[Mosinitis]

When zeroing a muzzleloader first you get the sights in alignment so there is a grouping on the target, located on or near the bulls eye. Then the fun begins as different amounts of powder are tried, differing thickness patching, even different diameter balls, all done methodically of course. When you are on the right track you can see the size of the group shrink until you find that combination your barrel likes and one big ragged hole is achieved. After that some minor tweaking of the sights will put you right on target.
That is the same attitude of methodology I use when working up a load for my center guns. Mosin may think its all a waste of time and that's okay, but at the end of the day I can be confident that when I miss, it's me, not my equipment.
Robin

You can see the difference on paper between GI ball ammo and match grade bullets like Sierra Matchkings. You can see the difference between shooting good and bad barrel. You will not see the difference between 24gr and 24.5gr Varget or Reloader 15........ and so on.

You can even prove this to yourself with someone to assist you. Take two loads and have someone give them to you without you knowing what you are shooting but he should keep track. Shoot first test 5 of each. Pick what you think shot better. Repeat this test 4 or 5 times randomly switching loads to be shot first. You will see that you will not pick the same load.

I don't mean to sound condescending, but a lot of what casual shooters do, believe or conclude is baseless. So is 80% of what is written in gun magazines and books.

 

[Robin]

You may be right Mosin. I am starting from a point where those things do make a difference. I can use FFF powder to find a good consistently accurate load, everything else being the same, switch to FF powder and see a markable difference. I can even make a good load of say 65gr's of FFF, drop down to 60gr's and see s markable difference, not only in the elevation of the impact but the actual group size.
I see no reason to change this approach when using centerfire ammunition, and I get a sense of personal involvement when I believe I have found the sweet spot for a particular barrel, or bullet.
Robin

 

[Mosinitis]

You may be right Mosin. I am starting from a point where those things do make a difference. I can use FFF powder to find a good consistently accurate load, everything else being the same, switch to FF powder and see a markable difference. I can even make a good load of say 65gr's of FFF, drop down to 60gr's and see s markable difference, not only in the elevation of the impact but the actual group size.
I see no reason to change this approach when using centerfire ammunition, and I get a sense of personal involvement when I believe I have found the sweet spot for a particular barrel, or bullet.
Robin

I use a short cut. I buy top of the line barrels and match grade bullets. I pick a powder which is not temperature sensitive. I done load development as well, but didn't find anything that blew my skirt up. The biggest factor in load accuracy is the quality and consistency of the bullets.

 

[meketrefe]

My Hornady book has 75 gr Amax COL 2.390
75 hpbt col 2.250
75 eld match col 2.390

would those numbers fit my Ar mag?

No. The max coal of the longest loading mags like PRI, some cmags, pmags, etc can go only as far as 2.3 or 2.31 in extreme cases.
One can gate a magazine and get and additional room for match loads or try to find a custom single stack ar mag that a guy used to make for dpms and can go up to 2.4 with a modified bolt stop and loosing the lrbo function.
But before any of that and loading any length one needs to find out how much freebore is available in the chamber for the bullet in question aa this will also determine the max coal for the round.

 

[holdover]

WOW! Theres a hell of a lot of good detailed information here! Thanks.

My concern, (because I dont know any better) was if I seated a round to deep into the case it could blow up from over pressure. If I seated a 77 gr sierra match king @ 2.260 , its not going to be to deep ? I was concerned about misloading a bullet , learning from your mistakes is not a good method with reloading .

 

[Mosinitis]

WOW! Theres a hell of a lot of good detailed information here! Thanks.

My concern, (because I dont know any better) was if I seated a round to deep into the case it could blow up from over pressure. If I seated a 77 gr sierra match king @ 2.260 , its not going to be to deep ? I was concerned about misloading a bullet , learning from your mistakes is not a good method with reloading .

It's not going to be too deep and the danger of compressed charges in 223 is overblown. All of my charges are compressed.

 

[holdover]

I use a short cut. I buy top of the line barrels and match grade bullets. I pick a powder which is not temperature sensitive. I done load development as well, but didn't find anything that blew my skirt up. The biggest factor in load accuracy is the quality and consistency of the bullets.

This is my philosophy in everything I do . If Im making clams casino, painting a room, fixing a car , whatever. I use the best materials I can get .

Im not rich, but when it comes to doing something right I dont pinch penny's, I dont shoot for mediocrity. I try to do the best job I can . Even though Im not a competition shooter by any means , My goal is to be as good as a competition shooter or close to it as I can.

 

[JamieZ]

2.26 is not a compressed load as far as depth of the bullet. Compressed loads depend on what powder you are using and at the same time the depth of the bullet. All my 223 reloads are compressed if I remember correctly,,,,when using Varget. Thats just the nature of the beast. Compressed doesnt mean over pressurized.

If you go on Hodgons reloading web page,,,the one you linked to above,,,,,,,,,,,,if the grain amount has a "C" after it,,,,its compressed

 

[holdover]

Ill take bullets' for a thousand Alex,

Sierra doesn't recommend match kings for hunting because????

 

[Mosinitis]

Ill take bullets' for a thousand Alex,

Sierra doesn't recommend match kings for hunting because????

This bullet is used by the military in a specialty ammo. I am not a hunter, so I can only guess why it is not recommended for hunting. It fragments into pieces upon hitting anything hard, like a bone.

 

[Will556]

Look up military Mk262 rounds. They have a few different versions of it out there. I’m sure they’ll get you in the right direction.

 

[meketrefe]

Slightly compressed extruded powders like varget are pretty common with 75-80gr match bullets.
just start slow and follow the measures and maximum coal also dictated by the lands.

Also might want to use hard brass as it will last longer as you get into the hot zone. Some also hold more powder
with Lake City (nato) brass and WCC being the highest capacity and it is hard brass that can take the
heat with pressures up to 63k psi w/o issues. However at those levels is not most likely the most accurate
round and brass will not last long.

Not all lake city is great. Lake city American eagle is good brass but it is soft brass and will not last 5 reloads
unless you go really mild. It is cheap or free at the bin so who cares but also doesn't play well with the heat.
The most consistent brass is probably lapua but the highest capacity and not really the first choice
to be mangled by a gas gun.
The 223 is a pretty forgiving round to reload, learn and get great results given one pays some minimum attention
to preparation and consistent reloads.

remember ....
A) know your rifle and chamber (COAL / lands)
B) Know your brass (don't assume all brass is equal in capacity or strength)
C) Know your bullets and other limitations (magazine coal)
D) Test spreads of charges and seating lengths and adjust (write down brass, capacity, load info and might want to save
a dummy empty round of your favorite bullet / coal for easy setup of the seating die next time you want more.

Good match bullets are more expensive and one likes to put them where they belong.
So, Lastly, missing is easy, anyone can do that. The complicated thing is to slow down and hit something and make sure you
feel confident of doing that consistently at any distance any time. IMO That is the most fun in shooting specially when
it comes from nicely and carefully loaded reloads at home.

 

[meketrefe]

Ill take bullets' for a thousand Alex,

Sierra doesn't recommend match kings for hunting because????

What mosinities said, it is quite unpredictable as it is not designed to stay together. it is designed to fly great but not to produce consistent
terminal behavior. still it can be devastating depending on the target.
However it has been observed that certain match bullets are great options for antipersonal purpose in very small bores like the 22.
Runds like Mk262 @Will555 mentioned above have been using sierra match king bullets for that purpose with federal gold medal and black hills being the best copies of that given performance. Nosler OTM is virtually the same.
But we have been also observing how the TMK (tipped one) is doing that is a better flier and it does even better at slow impact speed
thresholds that is what is intended for this. Or they do also great from a 11" pistol for shorter ranges. So they do fragment a bit
but they make a mess on the target.
That is why IMO the 77gr TMK is probably one of the best long range predator rounds for the 223, AI and so forth.
I don't hunt with the 223 anymore but, out west, the guys at the long range hunting forum have no problems popping coyotes as far as 600-700 yards with this round that can shoot flatter and further than other more obvious larger bore rounds. In my opinion they do better than the amax
vmax and elds.

I would expect you can find TMK tests in youtube from short SBRs that will give you an idea of the damage the rounds can make
at slow impact speeds. It also makes the 223 a very serious choice for an SBR imo.

Again, they are not hunting rounds or the best perpetrators for hard barrier or plates so keep that in mind.

 

[Mosinitis]

77 TMK is relatively new. They appeared only few years ago. I have a box, but didn't get to loading it. My biggest concern is that some of the tips can get loose and the bullet will become a flyer. This was actually the case with Hornady A-maxes. It was rare, but it happened. In my application this can ruin a day. I am letting others be test subjects. So far I am not hearing anything negative or positive about these bullets.

 

[meketrefe]

77 TMK is relatively new. They appeared only few years ago. I have a box, but didn't get to loading it. My biggest concern is that some of the tips can get loose and the bullet will become a flyer. This was actually the case with Hornady A-maxes. It was rare, but it happened. In my application this can ruin a day. I am letting others be test subjects. So far I am not hearing anything negative or positive about these bullets.

Never happened with the amaxes to me. still can happen as still have a few K's left of those 600 values packs.
But according to everyone reloading the tmk was done right from the get go and hornady fixed that with the ELD.
Is it possible? you bet, but probably so rare that will never have that kind of impact. These brands sponsor world champions
and they shoot the same bullets as everyone else and they would not want that kind of publicity on them.
I think there is also a risk a otm can be off by weight, meplat or some other defect but how often do you see those?
I trust Sierra bullets 100%. Hornady match are also in the same league.
I like bergers too but lately I do not see the point in spending more.

 

[Will556]

From what I believe the Mk262 was originally adopted for the Mk12 SPR. Which was later adopted by SOF for their shorter carbines when they realized it performed very well out of shorter barrels as well. Eventually they also designed Mk318 mainly for SBR’s. Though the Mk318 is a 62gr projectile and is a little more barrier blind and will penetrate hard targets more effectively and still expand well on soft tissue since it’s an open tip with a brass rear to penetrate hard targets.