Reloading 6.5CM for the JP LRP-07

[daved]

I'm expecting my JP LRP-07 in a couple weeks and would like to get a start on reloading some ammo for it. So some questions for those of you who have been reloading 6.5CM for this rifle:

Are small base dies actually required for trouble-free functioning? JP recommends them for all their auto-loaders but I'd like to avoid working the brass that much if possible. It seems like standard dies should be adequate unless the chamber gets very dirty.

What bullet tension do you use? I'm used to using 1.5 - 2 thou in my bolt guns. Is this too little for the semi-auto (SA)?

Are you concerned about distance to the lands or just load to mag length?

If you want to measure distance to the lands, what procedure do you use? It seems that my Sinclair and other tools used for this in bolt guns won't work in an SA. Do you use old school methods of (loosely fit bullet/cleaning rod) to check this?

Do powders (H4350, RL-17) and bullets (Berger 140TH/Lapua 139SC) popular in bolt guns work equally well in the SA?

When working up loads, where do you set the adjustable gas block?

Is it possible to tune ejection using the gas block to avoid scattering brass far and wide?

Thanks for any help-----

Dave

 

[spife7980]

Are small base dies actually required for trouble-free functioning? JP recommends them for all their auto-loaders but I'd like to avoid working the brass that much if possible. It seems like standard dies should be adequate unless the chamber gets very dirty.

Depends on your chamber and brass combo, no one can tell you for sure. I doubt you have issues with properly sized brass but anything is possible.

What bullet tension do you use? I'm used to using 1.5 - 2 thou in my bolt guns. Is this too little for the semi-auto (SA)?

Depends, its possible but plenty of people are using the same dies they use for their bolts and dont have any issues.

Are you concerned about distance to the lands or just load to mag length?

Depends on if the lands can be reached within the confines of the mag or not...
If not then go mag length, if they can then you need to measure for them to avoid jamming.

If you want to measure distance to the lands, what procedure do you use? It seems that my Sinclair and other tools used for this in bolt guns won't work in an SA. Do you use old school methods of (loosely fit bullet/cleaning rod) to check this?

Sure the sinclair tools will, you just need to get an ar adaptor.

Do powders (H4350, RL-17) and bullets (Berger 140TH/Lapua 139SC) popular in bolt guns work equally well in the SA?

yes

When working up loads, where do you set the adjustable gas block?

I would set it up for factory ammo if thats what youre shooting now, if not a couple middle charges and set it with that.

Is it possible to tune ejection using the gas block to avoid scattering brass far and wide?

Yeah, you can turn it off. Otherwise an auto loader will throw them out far and wide because... thats what it does.

 

[daved]

spife - Thanks for that comprehensive answer! AR adapters en route--

I'm surprised there are not more folks reloading for the LRP-07. Even JP has little or no info and some of their guys shoot the gun/caliber combo in competition!

Anyway, thanks again----

 

[Kiba]

There are a several of us here reloading 6.5CM for the semis, but there isn't an active dedicated thread for 6.5CM semi auto loads in the reloading depot.

My experience having reloaded lots of 6.5CM for 1x GAP10 and 2x JP LRP-07s...

Check the distance to the lands, but chances are even loaded to max AR mag length you won't be sticking a bullet in the lands. I used the Hornady curved OAL tool.

Never needed a small base die for any of my semis. I use a standard Redding Type S bushing FL die and bump about .0025.

When doing ladder tests, I load 5-6 extra rounds at the lowest charge and use those to adjust the gas block until it just barely locks the bolt back and then run the complete OCW/ladder at that gas block setting. The gas block setting will have an impact on velocity and therefore the ladder test, but if you pick the middle of a node even if you have to change the gas block 1-2 clicks from this initial "baseline" setting I find I'm still in the node and don't have to do a second OCW test.

You can run the 140s out of the semis, but at "decent" velocities I experienced very short brass life in terms of ejector marks and loose primer pockets in 2-3 firings. If you want your brass to live with the 140s you'll have to back the charge down.

123s and 130s in the semi are much easier on the brass, but if you try and push book max or slightly above book max charges that do OK in a bolt gun you'll still beat up your brass with ejector marks and loose primer pockets in 2-3 firings. With RL16 in my 22" LRP-07 and 123 Scenars the lower node that leaves brass looking perfect is at 41.6gr / 2860fps. Upper node is 42.95gr / 2925fps; no ejector marks but primer pocket life is about 2 firings less at that level. I ran as high as 44.0gr / 2990fps doing OCW tests and while there weren't any nasty ejector marks at 44.0gr the primer pockets did loosen up enough after the one firing to be noticeable when priming them the next loading. You could probably get 2-3 firings out of the brass at the 44.0gr level before the primers would be loose enough to leak. The rifle was still accurate at that velocity, depends on how much you want to abuse your brass.

The newer +2" gas port length is easier on the brass with the higher port pressures of the slower burning powders common in 6.5CM. A heavier buffer helps brass condition too. I have standard rifle length gas on both my LRP-07's and I'm running the LMOS carrier and 3x tungsten weights in the SCS for best brass condition. With the +2" gas system others have said 2x tungsten and 1x steel weights work well.

I'm having very good luck with RL16. RL16 pushes higher velocites at an equal charge compared to H4350, so you can get away with a little less powder (and according to Quickload a little less pressure at the gas port) which means better brass condition with RL16 while getting the same velocity as H4350.

I tried Varget and AR Comp too; both burn rather quick in the 6.5CM and thus have a lower port pressure which is easier on the gas system and brass (example: 6 clicks open needed to lock the bolt open with H4350 / RL16, but 11 clicks needed for AR Comp) but as you get near max charge Varget & AR Comp like to develop a nasty pressure spike and trash the brass. Both Varget and AR Comp go from OK looking brass to heavy swipes and ejector marks in just a couple of tenths because of that spike, not much room for error. Also, a near max charge of Varget or AR Comp is still shy of the velocity of a very moderate H4350 or RL16 load.

As far as chucking the brass... tune the gas block to lock the bolt back on an empty mag and then open it 1 click more to give things a margin for when the action gets slightly dirty. If you're worried about chucking the brass, get a brass catcher... I run a tactical brass recovery and it works perfect.

 

[daved]

Wow - thanks for that in depth response, Kiba!

I have no idea what the gas port length is on my build - there were no options - but I do have the H2 buffer, SCS, LMOS and detent adjustable gas block so it sounds like I should be able to follow your recommendations.

I also use a Redding Type S for my bolt guns so glad to hear I don't need to invest in a small base die.

It sounds like there may be an advantage in using RL-16 over H4350 so I may try working up a load with it. Alternatively,I have no problem with going to the 130 bullet. Depends on what Sportsmans' Warehouse has on the shelves--

I'm not certain I follow why the primer pockets don't last longer - is it just the fact that they are not supported by the bolt and chamber throughout the firing cycle? Do you use small or large primer brass? Supposedly the SP variety are less prone to the pockets loosening.

Thanks again for your help!!

Dave

 

[Kiba]

You probably have the +2" gas port, I don't think JP makes 6.5cm barrels with the standard rifle length location anymore.

Brass life in a semi auto is just shorter than in a bolt gun. I've played with gas blocks, buffer weights, buffer spring rates, and carrier weights over the years trying to maximize brass life, and I've always found that if I try to run my bolt gun loads in my semis the brass just takes a beating and is dead in a couple firings. To avoid swipes and ejector marks and get decent primer pocket life in the semis I've always had to back off the charges a bit compared to the bolt guns.

I have not tried any of the small primer pocket 6.5cm brass yet, but I also don't like running expensive brass in a semi auto... I don't feel I get my money's worth out of it given the shorter lifespan in a semi.

 

[Darqusoull13]

I'm expecting my JP LRP-07 in a couple weeks and would like to get a start on reloading some ammo for it. So some questions for those of you who have been reloading 6.5CM for this rifle:

Are small base dies actually required for trouble-free functioning? JP recommends them for all their auto-loaders but I'd like to avoid working the brass that much if possible. It seems like standard dies should be adequate unless the chamber gets very dirty.
They aren't required but they will help.
Are you concerned about distance to the lands or just load to mag length?
I load to mag length. It simplified my loading and since I'm using 140 and 147 ELD-M's jump isn't much of a concern.
Do powders (H4350, RL-17) and bullets (Berger 140TH/Lapua 139SC) popular in bolt guns work equally well in the SA?
4350 is a blessing for those of us in Texas. My loads are damn near the same velocity whether it's 100 degrees or 70 degrees. It's important to have a powder that wont spike in pressure when the temperature rises. I've had good results with Hornady factory 140's, Prime 130's *UNDER 80 Degrees F* as well as hand loaded 147's.
When working up loads, where do you set the adjustable gas block?
I set mine to lock back then open it 1-2 clicks.
Is it possible to tune ejection using the gas block to avoid scattering brass far and wide?
With the gas block set my brass usually ends up in a nice neat pile. It might not be close to me, but it's usually all together. I just wish more folks would man up and catch my brass
Thanks for any help-----

Dave

Congrats on the JP! I absolutely love mine.

 

[daved]

Thanks for the input, guys! I really hadn't expected that brass life would be significantly shorter in an S-A. Obviously, I'm going to have to modify my reloading practice and expectations.

My primary interest is the powder/bullet weight that works best in the 07 setup that I have (or will have shortly). I have a good supply of H4350 and Lapua 139Sc/Berger 140TH so I'll probably stick with them initially. I don't typically load beyond the mid-node so they may be fine.