6.5 PRC group size

[jmkasza]

I can't comment as there is a lack of information on your testing protocol. Nor on powder, primers, case brand, seating depth etc. Also the 110 is a short action?? And limit for coal??

All testing has been done from a bench, front and rear bags to a 100 yard target.

First batch of reloads (all of the shots on my first post) were using new Nosler brass and Fed 210's.

I did cast a wide net when it came to bullets and powder.. more or less trying to find something it likes to pursue load development. All loaded to book suggested COL; I adjust seating depth after picking a powder & charge weight.

Nosler AB Long Range	129	H1000
Nosler Accubond	140	H1000
Berger Elite Hunter	140	H1000
Berger Elite Hunter	156	N568
Berger Classic Hunter	135	H4831SC

 

[jmkasza]

I’d check it.

OK. Suggestions on how or a preferred method?

 

[jmkasza]

Here are today's targets. The 3-shot groups made me feel better at least. The first two were factory Precision Hunter 143gr loads and the rest were Berger 140gr Elite Hunter handloads. It was 70-84 while I was at the range today and I let the barrel cool between groups.

 

[lawman29]

Berger 140gr Elite Hunter handloads

Charge weight?

 

[jmkasza]

Today's handloads were Berger 140gr Elite Hunter, H1000, Fed 210 in Hornady 1x brass. Same as my other handloads, shoulder bumped back .003" and FL sized (expander mandrel).

 

[jmkasza]

Charge weight?

I'll send you a PM

 

[Clancy]

OK. Suggestions on how or a preferred method?

I hooked mine up with a torque wrench. It was within about 5%. My friend Grady’s was way way off.

It’s worth checkin.

 

[lawman29]

I'm currently working up a load for my son's 6.5 PRC. The rifle was built by Keith Kilby at Wyoming Armory; Defiance Classic long action, Hawkins Precision bottom metal & hunter mag, Kreiger #4 8 twist ~ 24" with mini-bastard, , McMIllian stock, SAMMI reamer. There is much info on the web etc about action length, with a short action you are limited in coal, just understand you may be jumping quite a bit. For your own info you should seat a dummy round to touching the lands. This will show you how far you're jumping...

I'm using Whidden dies, Lapua brass, H1000, Berger 140 hybrids, F210M and Garmin chrono for all initial testing. I'm pretty much done and have approximately 175 rds on the barrel. Generallly I would observe that the 6.5 PRC is a little finicky as compared to a 6.5 284 (the easy button...). I started with 97 rnds of virgin brass (3 unfired in the die box). That initial 97 rounds gave me info on velocity and seating depth - and I did not want to pick a load on virgin brass and with less than a 100 rnds on the barrel. The results bore this out.

Also I am using a front rest, rear bag and wind flag...

Initial loads velocities were as follows: 57.3 ~ 2900, 58.2 ~2960 and 59.2 ~3010.
After around 165 rnds 58.2 ~ 3030 and 59.2 ~ 3090-3100.
The increases are due to 3 factors, barrel speeding up, 1x fired brass and a new lot of powder was a little faster (used the old stuff for break-in and threw what was left away...).
Never any signs of pressure. The Hornady book shows 59.0 and 3100 for the 140's.

Seating depth: shot better closer to touch COAL ~ 3.08.
Neck tenstion: like more ~ .003 (290 bushing). My last test will be .004 (289 bushing).

Photo initial testing (have other charge weights 57.3 was ~ 2900)


SD = seating depth. CCB = cold clean bore


Primer test



Bushing test and seating (OG measuring with tool for seating depth)(DCB Dirty cold bore)
The groups are a little smaller with the tighter bushing. The 3146 velocity I consider an anomaly.
I will test once more at 200 with 290 & 289 bushing at OG of 3.381.

 

[jmkasza]

@lawman29

Thank you for the detailed post. I'm going to soak that in... sounds like I might get some range time next weekend too so I'll have to get a plan and do some loading this week.

 

[Straightshooter1]

About a year ago, just before I had my eye surgery, I had found a good load for my Berger 140 using 53.9 grs H4831sc (Lapua brass, Primer:Fed210, COAL: 3.023, .098 off the lands in a barrel with 1,900 rounds fired at the time) and decided to play with my tuner setting to get an idea of what results will look like when I change the tuner settings (tuner setting is the number above each target) for future reference on this load. I wrote down N565 on the paper that I used (normally I do use it), but it was actually the H4831sc. This load with the 30 shots gave me an SD of 4.6 and ES of 18, MV at 2,960 fps.

On that #2 target I liked what saw in the first 4 shots shots, then stupidly changed the way I held the gun going to a light/soft grip from a very firm grip thinking that would help me with a good trigger pull and not throw a shot. Well, there it is! LOL, not a good idea to change your mechanics when things are working.

 

[Straightshooter1]

I'm currently working up a load for my son's 6.5 PRC. The rifle was built by Keith Kilby at Wyoming Armory; Defiance Classic long action, Hawkins Precision bottom metal & hunter mag, Kreiger #4 8 twist ~ 24" with mini-bastard, , McMIllian stock, SAMMI reamer. There is much info on the web etc about action length, with a short action you are limited in coal, just understand you may be jumping quite a bit. For your own info you should seat a dummy round to touching the lands. This will show you how far you're jumping...

I'm using Whidden dies, Lapua brass, H1000, Berger 140 hybrids, F210M and Garmin chrono for all initial testing. I'm pretty much done and have approximately 175 rds on the barrel. Generallly I would observe that the 6.5 PRC is a little finicky as compared to a 6.5 284 (the easy button...). I started with 97 rnds of virgin brass (3 unfired in the die box). That initial 97 rounds gave me info on velocity and seating depth - and I did not want to pick a load on virgin brass and with less than a 100 rnds on the barrel. The results bore this out.

Also I am using a front rest, rear bag and wind flag...

Initial loads velocities were as follows: 57.3 ~ 2900, 58.2 ~2960 and 59.2 ~3010.
After around 165 rnds 58.2 ~ 3030 and 59.2 ~ 3090-3100.
The increases are due to 3 factors, barrel speeding up, 1x fired brass and a new lot of powder was a little faster (used the old stuff for break-in and threw what was left away...).
Never any signs of pressure. The Hornady book shows 59.0 and 3100 for the 140's.

Seating depth: shot better closer to touch COAL ~ 3.08.
Neck tenstion: like more ~ .003 (290 bushing). My last test will be .004 (289 bushing).

Photo initial testing (have other charge weights 57.3 was ~ 2900)
View attachment 1673635

SD = seating depth. CCB = cold clean bore
View attachment 1673638

Primer test
View attachment 1673639


Bushing test and seating (OG measuring with tool for seating depth)(DCB Dirty cold bore)
The groups are a little smaller with the tighter bushing. The 3146 velocity I consider an anomaly.
I will test once more at 200 with 290 & 289 bushing at OG of 3.381.
View attachment 1673640

That 58.8 and 58.9 looks pretty good to me . . . ???

 

[lawman29]

That 58.8 and 58.9 looks pretty good to me . . . ???

If you're referring to the first target, that was shot early on within about 25 rnds on the barrel, virgin brass and old powder lot. Think of it not as a charge node but a velocity node ~ 2980 -3000. 58.8 today is ~ 3060... That lower velocity node today is about 57.7 give or take. That lower node is still a possible option, but begs the question "why"? Why have a 6.5 PRC shooting 140s at 2980? I can darn near get there with a 6.5 284 or why not a straight 284 shooting 168s at 2960?? So why not use the case capacity to get to 3100 and let the big dog eat...

 

[jmkasza]

About a year ago, just before I had my eye surgery, I had found a good load for my Berger 140 using 53.9 grs H4831sc (Lapua brass, Primer:Fed210, COAL: 3.023, .098 off the lands in a barrel with 1,900 rounds fired at the time) and decided to play with my tuner setting to get an idea of what results will look like when I change the tuner settings (tuner setting is the number above each target) for future reference on this load. I wrote down N565 on the paper that I used (normally I do use it), but it was actually the H4831sc. This load with the 30 shots gave me an SD of 4.6 and ES of 18, MV at 2,960 fps.

On that #2 target I liked what saw in the first 4 shots shots, then stupidly changed the way I held the gun going to a light/soft grip from a very firm grip thinking that would help me with a good trigger pull and not throw a shot. Well, there it is! LOL, not a good idea to change your mechanics when things are working.

H4831SC is definitely on the radar for me. It was the powder for the 135gr Berger CH that I tested, but I think I will run it side-by-side with H1000 in the 140's next.

 

[jmkasza]

I measured the distance to the lands with the 140 and determined it to be jumping 0.093" (COL was 2.950). I should be able to shoot again this weekend, my plan is to test the following in 3-shot groups:

Re-test the 140gr at 2.950 (0.093 jump) same charge weight H1000
Test the 140gr at 3.000 (0.043 jump) same charge weight if the magazine allows

Open to suggestions for further testing, from what I've read the Elite Hunter shouldn't be as finicky about seating depth as the VLD and my intention is to stay within the limits of the magazine.

 

[Straightshooter1]

H4831SC is definitely on the radar for me. It was the powder for the 135gr Berger CH that I tested, but I think I will run it side-by-side with H1000 in the 140's next.

While that H4831sc worked well for me, I feel like I can't trust it to be consistent since that load is only 91% case fill. It was a powder that I just thought I'd try and see what happens for giggles and was surprised it did so well in this cartridge. I get just as good results (a little better actually with a heavier bullet, like the Berger 153.5's) with N565 where I can fill the case more and get the same velocity without the pressure limit I get with H4831sc. I like to get a close to 100% case fill when feeding from the mag.

I measured the distance to the lands with the 140 and determined it to be jumping 0.093" (COL was 2.950). I should be able to shoot again this weekend, my plan is to test the following in 3-shot groups:

Re-test the 140gr at 2.950 (0.093 jump) same charge weight H1000
Test the 140gr at 3.000 (0.043 jump) same charge weight if the magazine allows

Open to suggestions for further testing, from what I've read the Elite Hunter shouldn't be as finicky about seating depth as the VLD and my intention is to stay within the limits of the magazine.

Hmmmm??? I guess I shouldn't have mentioned what my jump was???. . . since jump has so little importance and seating depth is what really matters. Though, looking at both your COAL and jump, it looks like you've got plenty of room to seat out to the same COAL as I did (pretty long for a140 gr pills ). At least, with H1000 you can easily get you to 100% case fill without pressure issues. It'll be interesting to me to see what you're able to get.

 

[Straightshooter1]

If you're referring to the first target, that was shot early on within about 25 rnds on the barrel, virgin brass and old powder lot. Think of it not as a charge node but a velocity node ~ 2980 -3000. 58.8 today is ~ 3060... That lower velocity node today is about 57.7 give or take. That lower node is still a possible option, but begs the question "why"? Why have a 6.5 PRC shooting 140s at 2980? I can darn near get there with a 6.5 284 or why not a straight 284 shooting 168s at 2960?? So why not use the case capacity to get to 3100 and let the big dog eat...

I'm a bit surprised at getting 3100 fps out of a 24" barrel with H1000. Not that it can't be done as it appears your 59.2 grs is a compressed load and pressure might be just a tad over max. I've done that with RL23 giving me 3100 fps with some decent results (but with a 26" barrel).

 

[OmegaRed]

H1000
#1 - 56.0 gr
#2 - 57.0 gr
#3 - 58.0 gr

PIC BELOW:
140 Bergers
58.0 H1000 (might be too hot, it was shot in 45 degrees)
600 yards
26" barrel

This load was .75" at 200 yards off of a bipod and a rolled up sweatshirt for a rear bag. Another vote for 3 shot group with hunting guns. The barrel profiles generally can't take the heat for 5 shots without doing weird things.