300prc 230 Berger load development

[Bluepsylo]

For you seasoned and experienced people. I've been loading for this 300PRC. it's build on a Savage stainless action, 31" IBI 1:8 5R barrel with 3.850 AICS mag. Choate ultimate stock.

Currently fire forming new Lapua brass with 79.8grs of VV N570. Avg velocities @ 3015fps. Barrel has around 300 down the pipe so it should be broken in. It seems that I can put 2 shots tight but then always seem to pull the 3rd. Am I beating myself? Yesterday I wanted to confirm my zero @ 400yds and shot these groups. Thing it's a seating depth thing or is it me.

 

[Shoots 700's]

Are you expecting a one hole group at 400 yards.

 

[Bluepsylo]

Are you expecting a one hole group at 400 yards.

I'd like to see a tighter cluster.

 

[nealm66]

Maybe a reloading hiccup once in a while?

 

[nn8734]

Not sure if this is a serious post but in case it is, those are solid groups. My guess is that you’ve reached the limit of that system’s precision potential with those components (and possibly any combination of components).

What’s the purpose/application for this rifle?

Are you using it in F-Class or similar? hunting (its more then adequate as is for hunting)? “plinking” (a stupid ass term but one that’s used all too frequently so thought id throw it in).

 

[Shoots 700's]

You have a .29 moa group at 400 yards. I would be happy but, you can burn the barrel up chasing what your looking for if you want

 

[Bluepsylo]

Not sure if this is a serious post but in case it is, those are solid groups. My guess is that you’ve reached the limit of that system’s precision potential with those components (and possibly any combination of components).

What’s the purpose/application for this rifle?

Are you using it in F-Class or similar? hunting (its more then adequate as is for hunting)? “plinking” (a stupid ass term but one that’s used all too frequently so thought id throw it in).

It is a serious post. I respect your reply. I'm happy with the results but am always looking for ways to improve on my reloading and shooting. I'm just a regular guy who likes to shoot. I don't have time to compete at the moment (three little boys). I built this rifle to shoot a mile. That's a personal goal (consistently hit a mile 1 moa or less).

 

[Bluepsylo]

You have a .29 moa group at 400 yards. I would be happy but, you can burn the barrel up chasing what your looking for if you want

Thanks for the reply. The rifle shoots well. It just seems that I'll shoot two tight then "pull" one...

 

[nn8734]

It is a serious post. I respect your reply. I'm happy with the results but am always looking for ways to improve on my reloading and shooting. I'm just a regular guy who likes to shoot. I don't have time to compete at the moment (three little boys). I built this rifle to shoot a mile. That's a personal goal (consistently hit a mile 1 moa or less).

Well in that case, my suspicion is the problem isnt related you as a shooter or your load but something in the system itself.

ive seen that pattern of tight group w/flyer before in my R700 when i swapped my bedded McMillan A2 stock with a Cadex Dual Strike about 7 years ago. with the A2 id rarely have flyers however the dual strike (unbedded) threw one every forth shot or so.

To confirm/deny, I shot five 5-round groups using the rifle with the A2 and then five groups with the DS at 100 and 200 meters. With the A2 on, had two flyers total that were my fault while the dual strike had a flyer in every group but one.

I sold the DS and kept the A2.

 

[Bluepsylo]

Well in that case, my suspicion is the problem isnt related you as a shooter or your your load but something in the system itself.

ive seen that pattern of tight group w/flyer before in my R700 when i swapped my bedded McMillan A2 stock with a Cadex Dual Strike about 7 years ago. with the A2 id rarely have flyers however the dual strike (unbedded) threw one every forth shot or so.

To confirm/deny, I shot five 5-round groups using the rifle with the A2 and then five groups with the DS at 100 and 200 meters. With the A2 on, had two flyers total that were my fault while the dual strike had a flyer in every group but one.

I sold the DS and kept the A2.

Thanks, that's the kind of input I've been looking for. This barrel being 1.25" is heavy. I clearanced the stock to clear the barrel and I bedded really first 2" of the barrel back to the lug but I think the barrel maybe touching the stock due to flex on recoil? I'm gonna open it up a bit more and try.

 

[Ledzep]

Stop evaluating performance with 3 shots. You're making the assumption that the system is repeatable to a degree that variations can be identified and diagnosed with sample size = 3. It's not realistic.

In my experience/testing, short-hand evaluation that I am lukewarm confident in starts at 10 shot groups. True evaluation is 20-35 shots. I'm not saying you NEED to do 20-35 shot groups. I'm saying if you want to have statistical confidence in the performance of your loads you have to shoot a minimum of 18-20 shots. This is based off of tracking thousands of rounds worth of 20-50 shot groups and seeing when the data converges to a realistically useful level. YMMV.

Honest opinion: Keep what you have the same and just shoot it. Don't worry about "patterns" you see in 3 or 5 shot groups, and only diagnose problems when you can't hit your intended targets.

 

[Bluepsylo]

Stop evaluating performance with 3 shots. You're making the assumption that the system is repeatable to a degree that variations can be identified and diagnosed with sample size = 3. It's not realistic.

In my experience/testing, short-hand evaluation that I am lukewarm confident in starts at 10 shot groups. True evaluation is 20-35 shots. I'm not saying you NEED to do 20-35 shot groups. I'm saying if you want to have statistical confidence in the performance of your loads you have to shoot a minimum of 18-20 shots. This is based off of tracking thousands of rounds worth of 20-50 shot groups and seeing when the data converges to a realistically useful level. YMMV.

Honest opinion: Keep what you have the same and just shoot it. Don't worry about "patterns" you see in 3 or 5 shot groups, and only diagnose problems when you can't hit your intended targets.

I appreciate the input.

 

[spife7980]

and only diagnose problems when you can't hit your intended targets.

But... thats like every target I shoot at man!

 

[Bluepsylo]

My last two shots at 1040yds confirming my dope. I had to skew the BC a bunch to get it to Line up. That's the next battle...