JP-5 Tweaks and Tips?

[Jasonub]

14 minutes ago, PaleoMan said:

Yeah, I reported in a different thread on reloading...

 

I think one issue I had was that the OAL was quite short (1.157" IIRC), and folks were thinking that the bullet was jumping to the lands and being inconsistent. I did drop checks on the JP-5 and realized that the OAL could be up to ~1.132", so I made some rounds at that OAL. The std deviation was MUCH better.  Of course, I then realized the comment someone had made about the TF mag extensions won't work well with OAL > 1.125", so I changed the OAL again.

 

I also found some HP-38 powder (just a pound), in addition to the ton of CFE Pistol Powder I have. With my 125gr coated bullets, I found these results...

 

With CFE Pistol Powder, I got the best std. dev. and spread  with 4.8gr of powder. Getting about 143 PF. Seemed to work well with 70 degree lock and recoil seems OK (better than if I use Syntech 124 gr cartridges).

 

I got reasonable stats for a 4.0gr load (119 PF) and it shot very soft (4.2gr worked well too), using a 80 degree lock.

 

With HP-38, 4.4gr @ 152 PF worked well, and a 3.6gr load shot very soft (127 PF). In general, I seemed to get better numbers with the HP-38 (a faster powder).

 

In all cases, using 70 degree locks for the higher PF and 80 degree lock with lower PF, there never were any issues with feeding/ejecting of rounds. Ran flawless with easily 1000 rounds of testing and I even tried it at a Steel Challenge match.

 

On my Walther Q5, which also worked well with these rounds, I found that the stats were better with a hotter load, but manageable. I'll likely use the loads best for JP-5, as they were pretty good on the Q5 too. I don't want to build multiple loads, for each gun, if I can help it.

 

I'll likely settle on the 4.8gr CFE pistol powder. I do want to find some faster powders to try (Tightgroup, AA2,...) just to see how things work out, as a future powder to try. I also may try the low PF in a match to see how it works out.

 

In the future, I may want to try different bullet weights, but I've got quite a few of the 125gr Precision Bullets left.

 

It's been fun playing.

Thank you for the update.

 

What do you mean 70 deg is better at high PF? We're in IPSC country and we only need 125 pf to hit. Safely we target 130 pf. Im not planning to go higher than 135 PF.

 

So with 130 PF is it better to use the 70 or stock 80 degree lock as this will be the PF I'll be targeting? 130-135 maybe with 115 or 124 grain coated bullets and N32O or CFE.

 

Thank you for your helpful insights

 

Edited March 13 by Jasonub

[PaleoMan]

22 hours ago, Jasonub said:

Thank you for the update.

 

What do you mean 70 deg is better at high PF? We're in IPSC country and we only need 125 pf to hit. Safely we target 130 pf. Im not planning to go higher than 135 PF.

 

So with 130 PF is it better to use the 70 or stock 80 degree lock as this will be the PF I'll be targeting? 130-135 maybe with 115 or 124 grain coated bullets and N32O or CFE.

 

Thank you for your helpful insights

 

With the (factory) Syntech ammo, I was seeing about 150 PF.

 

With CFE Pistol powder, and after I adjusted my OAL to 1.125 so that I complied with what TF mag extensions recommended, I was seeing 140-153 PF, when running from min to max load. Those same loads on my Walther Q5 gave 129-138 FP.

 

With HP-38, running from min to max load, I was seeing 140-152 PF (132-141 PF on Q5).

 

So, I could get a good load for USPSA/IDPA on my Walther Q5, but the JP-5 was much higher (expected). I was finding that with the 70 degree lock, the cases were still going 6-10 feet. With the 80 degree lock, the cases were really going far.

 

When, I tried load below the min, I was still getting PF in the range 119-135 PF with CFE and 117-127 PF with HP-38. With those, the 80 degree lock seemed to throw brass pretty well, about 6-9 feet, and the shooting was very soft, with the really low loads.

 

In general, the HP-38, a faster powder than the CFE pistol powder, gave lower std. dev and spreads (4.4gr gave std dev 6.94, spread 18.24 fps). With the bunny fart loads, the spread and std. dev. was high 20-30 range, but they shot fairly tight groups), even though the POI was different (I need to check, because I think it was about 1" lower than POA at 20 yards).

 

I'm forming the opinion that, if I want to shoot with a PF in the 140-150 range, I'll use the 70 degree lock (I don't have a 60 degree lock), and if I want to shoot with 120-130 PF range, I'll use the 80 degree lock.

 

Since I'm initially using the JP-5 for Steel Challenge, I'm seriously considering to test in larger quantities, the lower PF load to see how reliable it works, as the recoil was very soft. I can make a higher load that, with the Q5, will be in the 130-135 PF range. If I have to use those loads with the JP-5, I'll use the 70 degree lock, as they will be pretty high PF.

 

I have to admit, after only shooting a .22 rifle for SC, and this being the first PCC shot, at the load I was running, I do have to focus more on managing the recoil. It was by no means as bad as other PCCs from friends that I toyed with briefly.

 

Oh, and lastly, a friend of mine has a (stock) competition MPX, which he brought to the range and I shot a few strings of 5-To-Go that I had set up, and then immediately did the same with my JP-5. Subjectively, both of us felt that the JP-5 was a little lighter, and I really felt that the balance of the JP-5 was MUCH better than the MPX. It made me feel good about my decision to get the JP-5.

 

 

 

 

[Jasonub]

2 hours ago, PaleoMan said:

With the (factory) Syntech ammo, I was seeing about 150 PF.

 

With CFE Pistol powder, and after I adjusted my OAL to 1.125 so that I complied with what TF mag extensions recommended, I was seeing 140-153 PF, when running from min to max load. Those same loads on my Walther Q5 gave 129-138 FP.

 

With HP-38, running from min to max load, I was seeing 140-152 PF (132-141 PF on Q5).

 

So, I could get a good load for USPSA/IDPA on my Walther Q5, but the JP-5 was much higher (expected). I was finding that with the 70 degree lock, the cases were still going 6-10 feet. With the 80 degree lock, the cases were really going far.

 

When, I tried load below the min, I was still getting PF in the range 119-135 PF with CFE and 117-127 PF with HP-38. With those, the 80 degree lock seemed to throw brass pretty well, about 6-9 feet, and the shooting was very soft, with the really low loads.

 

In general, the HP-38, a faster powder than the CFE pistol powder, gave lower std. dev and spreads (4.4gr gave std dev 6.94, spread 18.24 fps). With the bunny fart loads, the spread and std. dev. was high 20-30 range, but they shot fairly tight groups), even though the POI was different (I need to check, because I think it was about 1" lower than POA at 20 yards).

 

I'm forming the opinion that, if I want to shoot with a PF in the 140-150 range, I'll use the 70 degree lock (I don't have a 60 degree lock), and if I want to shoot with 120-130 PF range, I'll use the 80 degree lock.

 

Since I'm initially using the JP-5 for Steel Challenge, I'm seriously considering to test in larger quantities, the lower PF load to see how reliable it works, as the recoil was very soft. I can make a higher load that, with the Q5, will be in the 130-135 PF range. If I have to use those loads with the JP-5, I'll use the 70 degree lock, as they will be pretty high PF.

 

I have to admit, after only shooting a .22 rifle for SC, and this being the first PCC shot, at the load I was running, I do have to focus more on managing the recoil. It was by no means as bad as other PCCs from friends that I toyed with briefly.

 

Oh, and lastly, a friend of mine has a (stock) competition MPX, which he brought to the range and I shot a few strings of 5-To-Go that I had set up, and then immediately did the same with my JP-5. Subjectively, both of us felt that the JP-5 was a little lighter, and I really felt that the balance of the JP-5 was MUCH better than the MPX. It made me feel good about my decision to get the JP-5.

 

Wow thats comprehensive. Thank you for your insights. Im still waiting for my rifle to arrive and I want to be ready. 

2 hours ago, PaleoMan said:

 

 

Edited March 15 by Jasonub

[Jasonub]

Wow thats comprehensive. Thank you for your insights. Im still waiting for my rifle to arrive and I want to be ready. 

 

[PaleoMan]

You'll love it! A fabulous rifle.

 

I think JP suggests looking for an ejection of cases of about 2-3 yards. When yours comes in, you can try the lock you have (probably an 80) and see how it works with the loads. Mine came with the 80 degree lock and I bought the 70 degree lock. I'll likely buy (or better still try to borrow) a 60 degree lock to see how it works with my 140-150 PF loads.

 

 

[Jasonub]

Thank you PaleoMan

[PaleoMan]

I made some low powder, ~120 PF, loads. They were soft shooting with the 80 degree lock, seemed to group well, but the ejection was somewhat erratic. Some cases going straight out and landing about 4-5', but some only dribbling out and landing only about 3'. There were no malfunctions or issues, but I think still with the higher 140-150 PF loads I made.

 

I've got a ton of the coated 125gr bullets, so I'll use what I have. In the future, I'll probably try different weight bullets.

[Darqusoull13]

On 3/16/2024 at 5:48 PM, PaleoMan said:

Some cases going straight out and landing about 4-5', but some only dribbling out and landing only about 3'.

Are you using mixed brass? If so, are the pieces of brass landing closer stepped cases? Examples of such trashy brass being FM, Xtreme etc. 

[PaleoMan]

7 hours ago, Darqusoull13 said:

Are you using mixed brass? If so, are the pieces of brass landing closer stepped cases? Examples of such trashy brass being FM, Xtreme etc. 

Good catch!

 

I sort my cases by headstamp and then make batches. Well, I ran out of R-P cases, and switched to Federal just before this chrono-ing and testing. Unfortunately, I have a container of miscellaneous cases (which are only used when setting up my press as depriming cases or as OAL/crimp measuring cases), that got accidentally loaded into the case hopper of my Dillon 650, along with the Federals. Argh!

 

I was able to separate out enough of the Federal only cases for chrono-ing, but for doing the eject testing there were other cases mixed in. I guess that is likely the cause - though I'm surprised of the effect being that pronounced.

 

I have been wondering about my amount of crimp. I've taken some factory ammo and measured the crimp the best I could, and then set my crimp to the same (it's hard to measure). The federal cases appear to be about 0.375" at the crimp location. My reloads are about 0.379".

 

Anyone have thoughts on that? I've heard folks mention about crimp affecting consistency, though I think they were talking about too much of a crimp.

 

 

[Darqusoull13]

15 hours ago, PaleoMan said:

Anyone have thoughts on that? I've heard folks mention about crimp affecting consistency, though I think they were talking about too much of a crimp.

 

 

Dillon has very detailed instructions on setting up crimp in their set up guide. Generally though, don't bother adjusting crimp in pistol rounds after it's set up properly. 

As far as trash brass, some pistols won't even chamber certain brands of brass reloaded with bullets over x weight or seated past certain depths. The reason is the case isn't tapered like a proper 9 mm case but instead stepped. Reloading into that step causes a bulge that is over chamber dimensions.

If you're using mixed brass and have too many of those cases, either find another source of brass or try to cull as best you can. If you're using a Hundo case gauge that's where I'd recommend giving the head stamps a once over for the final check. Toss the trash brass in "zero only" or practice piles. 

[PaleoMan]

I usually stick to well known or popular cases (e.g. R-P, Federal, Blazer, Sig,...) and sort them into containers. I have one container for lesser known brands or ones that I just don't see a lot of (e.g. Aguila, Hornady,...). Then, I have one container for everything else (some no-names and some military head stamps). Those will end up going back to the range - they collect brass and use it to fund shooting programs for kids.

 

I load up the case feeder with one container, and if it runs out, I transition to another container, and start marking the heads with a different permanent marker.  I just had a brain fart and accidentally poured some of the junk ones into the hopper - wrong container.

 

I spent quite a while separating the cases back out. Argh!

 

I'm still curious as to why I get some larger spreads and std. dev. I'm not sure if it is my technique, primers, bullet selection, powder, OAL, crimp,...  I think the OAL is fine (1.125" for the JP-5 use, of which I could go up to ~1.132" from checking the seating). The crimp is close to the SAAMI spec.

 

A friend of mine has a 750 and we were thinking of having him load with my powder and bullets to see there is a difference in technique. He also has Berry bullets and we were going to try those vs my coated bullets. Fortunately, he's anal an engineer, like me, so we have fun researching into this.

[Jasonub]

In our country top guys using jp use 115 grain coated bullets. they say it's softer and back to target quickly. N320 powder and 135-140pf

 

Edited March 21 by Jasonub

[PaleoMan]

22 hours ago, Jasonub said:

In our country top guys using jp use 115 grain coated bullets. they say it's softer and back to target quickly. N320 powder and 135-140pf

 

Interesting. Do you know what lock they used?

 

[Jasonub]

Yes they use the 70 degree lock piece. They use coated heads as sometimes 115 gr fmj weights in the chrono to be less than 115. And in ipsc rules, its unsafe for rifles and they zero you I guess.

 

The coated ones never hit 114. its usually a little more than 115 and tops at 117 gr

 

Edited March 27 by Jasonub