25 prc? 25-7 prc? Experiences? Gotchas? Intangibles?

[schmidty3]

Well iv

See how it does with 57.5…but I’d load up 10-15 not a bunch. I would change powders if it’s not up to your standards before tweaking seating depth or anything. Then change bullets if it’s still not good after 2-3 different powders.

I've got 8 lbs of n565. 800 135s and 200 133s. I do have a lb of n570 and some old h4831 (long cut ).

Gonna try to get that n565 to work. I do think i need to jump them a bit more.

Been playing with my dad's seekins 6.5 prc. It really settled down around 60 rounds. I dont think it's unreasonable for a gun to take 50-100 rounds to break in, but im new to fancy barrels.

Im going to clean it back to bare metal and send a bunch more. Thatll probably do it.

 

[schmidty3]

A little update.

Realized that my seating depth was around .005" off. (My initial assessment was hasty).

Tried .30-.100 off in 4 steps with the 135s and 57.5 gr n565

Shots 3 -6 of the day out of a bare barrel are captured as number 1s at 30, 55, and 75 off. After those 3, the group seemed to drop ~1 inch lower. Either fouling or still breaking in i guess.

Omitting those, the groups were .6-.7" or so. Shot the ladder in a snake order. At the end I put the 3 remaining 133s I had in with the 2 others. That made a pretty decent 5 shot group.

So we are showing some promise.

My velocity ES's are still pretty inconsistent. Averaging them all, they probably would land around 2980ish. But my low was 2936, and my high was around 3020 I think. And the ES's within seating depths was at least 20-30 (or more).

We are still breaking in. And we have virgin brass.

Im going to try bumping up the powder charges and adding dry lube to the bullets until the brass is formed.

 

[Bluefish]

I too did some testing this week. 134 eldm, 22” 1:7 twist, h1000, 56g was 2910. Bumped up to 56.5 and it was running 2947. Es and sd are a little bigger than I would like. I assume that may get better if I bump up the charge a little more. Overall pretty happy with the speed. I can probably get more, but 2950 was my goal. I do think I will go shorter when this barrel is burned out. I have a 20” contender and that with a scythe on it is shorter than the 22” tikka, no can.

 

[khuber84]

23in 7.5tw brux, Bat bumblebee with UM 3.150 mag box. 200k freebore chamber. 60.0 H1000 is right at 3110, shoots pretty good there but it's a lil too warm for my likings. Will drop it down to the next node. I have a late season cow hunt lined up, the ranch requires monos, so I'm gonna get some the 117gr copper rose bullets and see if I can get them to shoot well up around 3200-3250.

 

[schmidty3]

23in 7.5tw brux, Bat bumblebee with UM 3.150 mag box. 200k freebore chamber. 60.0 H1000 is right at 3110, shoots pretty good there but it's a lil too warm for my likings. Will drop it down to the next node. I have a late season cow hunt lined up, the ranch requires monos, so I'm gonna get some the 117gr copper rose bullets and see if I can get them to shoot well up around 3200-3250.

I guess I had a serious oversight on my build. Didn't even think about freebore. Mine is seriously short. My coal at 30 off is 2.900". Really cutting into my capacity.

Looks like I'll be around 3000 fps max. Anything over 3050 started showing pressure signs. 23.25"

Also not sure what's going on... my velocity is all over the place. Im talking 60-80 fps for 3 shots.

Using the same dies (sac), brass, close to the same charge, and same primers on my dad's seekins 6.5 prc and it is pretty good.

But even with that... still .4" 3 shot group

I loaded up 50x of a lighter charge, 57 gr n565. Im just gonna shoot the thing for a bit. Might even take it to a prs next weekend. Limit to 5 shots a stage or so.

Im wondering if it just needs to foul up more. Ive been cleaning it back pretty good during for the first 3 range trips.

Im loading TO THE KERNAL with a fx 120 scale. I also used redding dry lube on my bullets this time.

Or it could just be the fireforming process. But the cases aren't moving much. Like .001-.002 from new to fired

I don't know what's going.

Im painting it now! Hopefully it turns out.

 

[khuber84]

If the es is BIG I'd try a different charge, or primers. 210M usually do the best for me, or a BR2, BR2 are a hotter primer in my testing, closer to magnum primers.

 

[eoperator]

I guess I had a serious oversight on my build. Didn't even think about freebore. Mine is seriously short. My coal at 30 off is 2.900". Really cutting into my capacity.

Looks like I'll be around 3000 fps max. Anything over 3050 started showing pressure signs. 23.25"

Also not sure what's going on... my velocity is all over the place. Im talking 60-80 fps for 3 shots.

Using the same dies (sac), brass, close to the same charge, and same primers on my dad's seekins 6.5 prc and it is pretty good.

But even with that... still .4" 3 shot group

I loaded up 50x of a lighter charge, 57 gr n565. Im just gonna shoot the thing for a bit. Might even take it to a prs next weekend. Limit to 5 shots a stage or so.

Im wondering if it just needs to foul up more. Ive been cleaning it back pretty good during for the first 3 range trips.

Im loading TO THE KERNAL with a fx 120 scale. I also used redding dry lube on my bullets this time.

Or it could just be the fireforming process. But the cases aren't moving much. Like .001-.002 from new to fired

I don't know what's going.

Im painting it now! Hopefully it turns out.

I would be moving to a shorter bullet like 133eh if my rifle had a short fb, and trying lower powder charge weight if es was bad.

 

[SloppyJ]

Tagging along on the load dev to see what you get figured out and what those ES/SD numbers do.

 

[schmidty3]

I would be moving to a shorter bullet like 133eh if my rifle had a short fb, and trying lower powder charge weight if es was bad.

With my redneck lands checking tool (a blue sharpie)...it really seems like the 133s and 135s have about the same depth to the lands

Trip before last I put 5x 133s into 3/4". 57.5 gr n565. 0.050 off.

3013
2992
2976
2963
2947

ES 66

Lol

Other shots on the target were a seating depth test at 57.5 gr with 135s. Velocities all over.

Soooo....im going to stop cleaning it. Let it get all "seasoned" up in there. Maybe going from clean to dirty is taking more shots then anticipated. But countering that thought...my cold bore super clean barrel did lay a bullet perfectly onto my zero from the trip prior

 

[schmidty3]

Maybe neck tension???

We are sort of guessing on a wildcat.

Im running the SAC die with the expander mandrel.

New virgin brass run thru the sizer seems to be about .284-.285 diameter on the neck.

Loaded, that virgin brass is .287-.2875 (sample of one ).

.002 to .003 neck tension seem ok? I think thats within reason.

(Measured with cheapo calipers)

 

[Ganderzone]

Maybe try a uni throater from ptg to extend the freebore