New to reloading

[birddog67]

I started loading for my 308 Ar 10 24 inch barrel and my 300 ultra semi custom SPS , I started loading the 308 using serria load data chose 168 match king reloader 15 , worked up to 43.4 with .68 groups at 100 yards , my chrono was giving me Ava @2760 , I have shot federal box ammo match kings 168 thru the chrono speed 2720 with groups closer to .50 ,these are 5 shot groups , my question is I am 1/10 grain over max no presser signs , another loader I know says loads in most books are for bolt guns , and I might be pushing my AR to early bolt problems , my questions are any loaders loading from bullet manuals how close are they to max loads ? Also tried 178 amax with AR Comp powder getting right @ 2590 with 37.5 grains 3/4 groups at 100 went up to 39 gr starting load had the best group but my speeds where all over the place might be my chrono,

Then there is my 300 ultra , this gun has given me head aches , started,loading 185 Berger VDLS OAL 360 loaded 94 gr retumbo chrono have me 3220 all under and inch , went up to 96.5 best group was the 94 grains , best group was shot in the morning in Houston tx , shot them same loads Friday , velocity where good they where all within 15-20 FPS but gun would not group , was this due to temperature 20 deg difference ? This gun has shot well but now has about 500-600 rounds thru it regular contour barrel gets hot quick , I let it cool between shots , not sure what going on or I might just be me , I just thought I would be harder to get the gas gun to shoot good just starting to reloading and the bolt would be easier ? Just getting frustrated with my 300 ultra and suggestions would be greatfull

308 using max load out of manuals ?
300 ultra what to do next ?

 

[AtownBcat]

I started loading for my 308 Ar 10 24 inch barrel and my 300 ultra semi custom SPS , I started loading the 308 using serria load data chose 168 match king reloader 15 , worked up to 43.4 with .68 groups at 100 yards , my chrono was giving me Ava @2760 , I have shot federal box ammo match kings 168 thru the chrono speed 2720 with groups closer to .50 ,these are 5 shot groups , my question is I am 1/10 grain over max no presser signs , another loader I know says loads in most books are for bolt guns , and I might be pushing my AR to early bolt problems , my questions are any loaders loading from bullet manuals how close are they to max loads ? Also tried 178 amax with AR Comp powder getting right @ 2590 with 37.5 grains 3/4 groups at 100 went up to 39 gr starting load had the best group but my speeds where all over the place might be my chrono,

Then there is my 300 ultra , this gun has given me head aches , started,loading 185 Berger VDLS OAL 360 loaded 94 gr retumbo chrono have me 3220 all under and inch , went up to 96.5 best group was the 94 grains , best group was shot in the morning in Houston tx , shot them same loads Friday , velocity where good they where all within 15-20 FPS but gun would not group , was this due to temperature 20 deg difference ? This gun has shot well but now has about 500-600 rounds thru it regular contour barrel gets hot quick , I let it cool between shots , not sure what going on or I might just be me , I just thought I would be harder to get the gas gun to shoot good just starting to reloading and the bolt would be easier ? Just getting frustrated with my 300 ultra and suggestions would be greatfull

308 using max load out of manuals ?
300 ultra what to do next ?

is 500-600 rounds getting close to the average life of an ultra? I have heard stories of them being very hard on barrels.

 

[Kevin Thomas]

Birddog,

If you're new to reloading, you didn't do yourself any favors by starting with an AR10. Simply put, reloading for gas guns is a form of advanced handloading, so you're starting in the deep end. That said, yes, they can be extremely good shooters. As you've probably seen, there are a number of books that have separate sections for gas guns and bolt guns, but it's not as much of a pressure issue as you may imagine. The reason for the two sections is to isolate those powders which are suitable for gas guns, specifically the M1 and the M1A/M14. Both of these (the M1 in particular) have very specific needs concerning burn rates. Too slow a powder, even it it is loaded well under standard pressure limits, can and will damage a Garand. They can also be fairly brutal on the M1As as well. Damage to the op rods is the question here, and it's caused by too high a port pressure; the result of choosing a powder with too slow a burn rate for these rifles. The gas system of the AR family, on the other hand, actually handles this issue a bit better, and isn't as subject to port pressure problems. Still, choosing a correct powder will give the rifle better service life, and prevent some of the problems which could pop up otherwise. Stick with Varget, RL-15, 4895 or others in this burn rate, and you should have no problems. As far as pressure itself, the AR10 actually has greater surface area than the M700 when we're talking bolt lugs; they're very strong rifles. Still, the system of operation mandates certian limitations, and this is what you're into. Stick to the mid range powders, keep the bullet weights around 175 or less and ALWAYS full length size, and you'll eliminate 95% of the potential problems without having to experience them first. Trust me, it's better that way.