6 Creedmoor RPR in One Spot

[quickdraw]

Well I've spent several days searching everywhere trying to gather information on setting up and developing an RPR in 6 Creedmoor. The ongoing RPR threads are 70% 6.5, 25% .308 and 5% of ...well I don't really know. So here it is in one spot.

I've been shooting a 1st Gen 6.5CM RPR for the past 2 years and have been happy with it but when the 6CM came out it intrigued me. I've had it in my cart 3 or 4 times only to back away. Well I finally found a reason to order one, I'm looking for less recoil to be able to acquire the target and re-engage. My new RPR will be here on Monday and I'm thinking about trying to run it in a local match next weekend. Brass, bullets, dies and modified case all got here today so I'm off and running.

From research and personal expense with the 140 ELD-M bullets in 6.5 I decided to go with the 108 ELD-M for my bullets. I also decided to stay with Hornady brass as I've had good case life in the 6.5 world. I'm already flush with H4350 powder and FGMM 210 primers so that was easy. I bought another set of Redding Competition Bushing dies to stay with what I already know. So I'm set to develop loads next week.

My 1st Gen got a Seekins forehend, Little Bastard brake, Timney trigger and ambitious safety along with the aluminum bolt shroud. This time around everything is already there except the Timney trigger which will be here on Monday. I'll mount one of my Vortex PST II 5-25x50 scopes with NF Ultralite rings because well I already have everything from previous builds.

The area where information gets thin to non-existent or quickly off track is in load development for the 6mm Creedmoor. One piece of info out there is that factory 108 ELD-M is running 2960fps. I'm thinking of probably staying in the high 2900's to low 3000's so that seems to work. Looking through Hornady load data and trying to start a tad low I'll probably start with 41gr and work up by 2/10's a pop. I'll probably start at .020 off of the lands and see what that gets me as well.

So current 6CM RPR owners, help a guy out. What can you share to head me and others in the right direction? Is there something in the direction I'm heading that I need to rethink or flat out change? What can I expect out of this caliber in an RPR? At 3k fps with H4350 when will I need to prepare for a new barrel?

 

[bohem]

The 6mm's aren't the hands down match favorites for no reason. The 6mm Creed is an excellent cartridge and it runs reliably, accurately and easily in pretty much everything.
Barrel life is what you make of it. If you use H1000 and load for 2950-3000fps from a 105 class bullet then 2000-2500rd isn't unreasonable. If you use H4350 at the same speeds then 1700 is more the norm. If you load RL26 or H4350 to push for the PRS speed limit then you're looking at 1100rds...

If you push it hard and hot, even when loading the H1000 soft then you're still going to get a short barrel life.


Load dev for a 6 Creedmoor is incredibly simple. Recently I got a text from a customer who took his load from 6.5 Creedmoor, backed down 1/2 grain and just loaded up 50 rounds. First group that was zeroed on paper was in the low 0.3" range at 100yd.
I am about to start a run of 6mm Creed barrels, it is one of our more popular items. Probably #2 or #3 to the 6.5 Creed

 

[b6graham]

1500 maybe

Tons of info in reloading forum about 6 creedmoor. Doesnt matter a whole lot what platform. Start low and work up to a node. One pet load wont work in another barrel. No one can give you the perfect solution

 

[FUNCTIONAL]

I agree every rifle is different but with h4350 my sweet spots have always fallen in 43.3-43.6 with 105gr bullets.

Also try the 107 smks. Not very popular on these boards but have been very consistent for me against bergers, rdfs and eldms.

 

[quickdraw]

I agree every rifle is different but with h4350 my sweet spots have always fallen in 43.3-43.6 with 105gr bullets.

Also try the 107 smks. Not very popular on these boards but have been very consistent for me against bergers, rdfs and eldms.

What velocity are you getting with that load? I would expect the Hornady load data to be very conservative the same as it is for the 6.5CM. The current data doesn't even get up to what their original load was when they brought out the 6.5CM and printed the recipe on the box.I'll run everything through the LabRadar while I start testing. I'm really looking for a node around 3000fps every bit as much as good groups. I don't chase usually speed but one of the reasons I'm trying this caliber is to lessen vertical dispersion.

 

[Steelhead]

Over the years I've just loaded mine with 41gr of H4350 behind the 105 Berger Hybrid. If you load much hotter than that, your barrel life is going to be significantly less. Ive been using this load for 6 or 7 years now and have gotten great barrel life and accuracy from multiple platforms, including the RPR.

 

[Rebel Rooster]

I load 41.9 gr of H4350 in Petersen brass for both my RPR and GAP 6mm creed moor, but 41gr even would probably be just about fine too. My groups were pretty much the same from 41 to 42; I just found the best SD/ES at 41.9. Velocity out of the GAP is like 3060. I haven't chrono'd the RPR.

 

[quickdraw]

I picked up the rifle today. Came home and gave it a thorough cleaning, changed out the trigger to a Timney, pulled the scope base cleaned/loctite and torqued, checked all of the other bolts for torque and put on the bipod rail and sling QD mounts. So the rifle will be 100% after the rings come in tomorrow.

Measured the base to lands in the chamber and decided to go.020 off to start. Checked the new brass and decided to FL size and neck size 40 new cases to start. Primed the cases and will start with H4350 at 41.0gr and work up. Will also load 5 at 40.6 for a little break in to start. I'm hoping to get my load and dope in the next few days and maybe run this rifle in a match this weekend.

 

[FUNCTIONAL]

What velocity are you getting with that load? I would expect the Hornady load data to be very conservative the same as it is for the 6.5CM. The current data doesn't even get up to what their original load was when they brought out the 6.5CM and printed the recipe on the box.I'll run everything through the LabRadar while I start testing. I'm really looking for a node around 3000fps every bit as much as good groups. I don't chase usually speed but one of the reasons I'm trying this caliber is to lessen vertical dispersion.

3085fps is about average for those charges. My barrels are typically 24" and have been mullerworks, bartlein and hawkhill. I don't agree with whoever said above 41gr is going to kill the throat. All my barrels (except one which i believe was bad metal) have been 1200-1500 competitive rounds. I still have a 5r bartlein at 1800 and no loss in velocity or accuracy.

It may be a velocity sweet spot at 3085 rather than charge weight as all bullet types (inclyding 110 sierras) have shot best at that velocity area. The sierras if I remeber right took about 44gr of h4350 to hit 3085 in a 22" barrel but it burned out in 400rds. I suspect it was a mix of a poorer steel and how hot that load is.

 

[quickdraw]

To me charge weight is just a relative measurement. I believe in velocity nodes and follow velocity to maintain accuracy once it is determined in a particular barrel. I've never really gone after a particular velocity as a goal, I've always looked for accuracy at a usable velocity. My reason for going to 6CM though is to take advantage of these higher velocities to lower the potential vertical dispersion, if that makes sense. I understand that speed kills a barrel so I still won't be looking for the top end of the spectrum but I'm willing to trade off a little added expense in barrels to gain an advantage related to a flatter flying bullet.

 

[quickdraw]

I got out today to start break-in and load development. Loading H4350 powder, Hornady brass, FGMM primers and Hornady 108ELD-M bulleys. 1st 5 rounds at the lower end of the tables at 38.0gr. and 2784fps. Next 5 were 39.0gr at 2879fps. From there I jumped up to 41.0gr and 3003fps. 41.6 and 41.8 settled into a node at 3050 and 3053fps. Finished off at 42.0 and 3060fps. Based on velocities and 1/2moa groups I decided to split that node and load 41.7gr.

I would imagine the barrel to speed up a bit and also settle in a bit over the next few hundred rounds so around 250-300 rounds I'll re-measure the base to lands and run velocities again while shooting a few groups and then call it done for the remainder of the barrel. At 3050'ish I'm hoping for 1,500 to 1,700 rounds on this barrel....we'll see. I plan to try this as my match rifle and use my 6.5CM RPR as the practice rifle.

 

[quickdraw]

Back out again today for final prep before the match tomorrow. I loaded the rifle into the Kestrel, input the bullet from the bullet library and used the Litz custom curve data and then input the velocity. Range conditions were less that favorable but I needed DOPE. Temperature at 96*, winds from 1:00 to 2:30 varied from 15 to 20mph on a range with a varied terrain to keep the wind switching. Loaded 10 and dialed dope from the Kestrel shooting 2moa targets. Between the rifle and the Kestrel it was near dead on at 7 distances out to 870y. 7 of 10 hits with 3 close wind call misses but elevations were great, 1 click off at the worse at the longer distances. Inside of 650 was great. With the conditions I'm very happy and ready to run it tomorrow in the match.

Ruger builds a nice rifle that shoots way above it's price point. Getting the 6CM up and running was even easier than the 6.5CM was a few years ago. Now to get on to having some fun. I can see why there are so many 6mm junkies out there.