RPR 6mm Creedmoor freebore?

[mensajd]

Recently purchased an RPR in 6mm Creedmoor. Max OAL in the Magpul pmags is around 2.810" which resulted in a relatively hard jam into the lands with Berger 105gr hybrids. Using 41.8 H4350 and CCI BR-2, my initial 3 shot group (after sighting-in) was around 0.19" - that plus the factory Hornady 108gr eld shot in a 5-shot group of 0.69" is all the grouping data that I have. Only 30 rounds through so far (including letting a friend shoot 6 rounds into a sub-moa group using factory Hornady loads). The factory rounds weren't into the lands even though they were just under 2.80" OAL. Loaded some Bergers at 2.80" and they are still lightly jammed but I haven't been able to shoot them yet. Local range is closed for lead cleaning until August 4 so I have put shooting stuff aside.

Question: anyone know the RPR 6mm Creedmoor freebore? Seems like it might have been optimized for 105gr bullets in mag length loads with a decent amount of headroom for chasing the lands. 115gr DTAC bullets might be problematic depending on ogive shape but will definitely eat into powder space...

 

[Patrick Comte]

What's your base to ogive length?

 

[fatelvis]

I just measured my RPR's throat last night and found that Hornady's 108 ELD match ammo is jamming into the lands .16"!! (Not .016"). I checked it 3 times, because I thought for sure that Ruger and Hornady MUST HAVE teamed up and compared notes on dimensions, when developing the 6mm Creed. Do you think this is something that I should just load accordingly for, or should I send my rifle back to Ruger for a reaming?

 

[Dgd6mm]

The first thing I would do is talk to Ruger to see what freebore length they supposedly chamber the 6mm Creedmoor too. Second if it comes up to their measurement then I would consider either a uni-throater and throating it myself to a dummy round, or taking it to a Smith and letting the Smith throat it.

 

[fatelvis]

Does a gunsmith need to remove the barrel to re-throat?

 

[Rob01]

I just measured my RPR's throat last night and found that Hornady's 108 ELD match ammo is jamming into the lands .16"!! (Not .016"). I checked it 3 times, because I thought for sure that Ruger and Hornady MUST HAVE teamed up and compared notes on dimensions, when developing the 6mm Creed. Do you think this is something that I should just load accordingly for, or should I send my rifle back to Ruger for a reaming?

The Ruger should be using the .183 SAAMI freebore and my custom Creedmoor uses that and the factory 108 ammo at about 2.800" is .020" off the lands. So if you are jamming the 108 ELD factory ammo .16" then that is a super short chamber. I would check with Ruger.

 

[fatelvis]

I called Ruger and they offered up no headspace numbers, but they said they'd like the rifle back to take a look at it. I'm really hesitant to send it back, now that my F-class season started, but I would like to load the 105s and 108s out to where they should be, and not pushed back into the powder space in the case. Is it difficult to ream a throat by hand, without a lathe?

 

[Ralph Meech]

I just measured my RPR's throat last night and found that Hornady's 108 ELD match ammo is jamming into the lands .16"!! (Not .016"). I checked it 3 times, because I thought for sure that Ruger and Hornady MUST HAVE teamed up and compared notes on dimensions, when developing the 6mm Creed. Do you think this is something that I should just load accordingly for, or should I send my rifle back to Ruger for a reaming?

My rpr shooting factory 108's was jammed .100+. It was pulling bullets when attempting to unload. I sent it back to Ruger, they put a new barrel on it. New barrel with Berger 105 hybrids is 2.044 cbto which puts me .005 off the lands. Still not happy with the length.

 

[Dusty Stevens]

any gunsmith can set the throat to fit whatever length you want in very short order. ruger dont have a clue what youre trying to do. they order saami reamers and thats what it is.

 

[jaygorski]

If your Hybrid loads are sporting a 2.153" BTO you're looking at a .104fb

 

[Dusty Stevens]

If your Hybrid loads are sporting a 2.153" BTO you're looking at a .104fb

measured with who's tool? and how much jump does he have at that measurement on his exact tool?

 

[fatelvis]

I found that I cannot use the Hornady 108 ELD at all, due to it being pushed so far back into the case. Using Berger 105hybrids, I can seat them to an OAL of 2.71" and still get a few thou clearance, and still only have the boat tail below the neck. I have to find a local smith soon. I don't feel like sending it off in the mail.

 

[Dusty Stevens]

Seat a bullet with the pressure ring well above the neck shoulder junction and have your gunsmith throat it to match that bullet. Wont take long

 

[Ralph Meech]

My rpr shooting factory 108's was jammed .100+. It was pulling bullets when attempting to unload. I sent it back to Ruger, they put a new barrel on it. New barrel with Berger 105 hybrids is 2.044 cbto which puts me .005 off the lands. Still not happy with the length.

That was measured with my Hornady oal gauge and my cheap calipers and my sense of feeling when the bullet stops. I need to find a smith in Phoenix to get a look at it.

 

[jaygorski]

measured with who's tool? and how much jump does he have at that measurement on his exact tool?

I use the Hornady oal gauge, I usually jump them .024" and that puts the pressure ring right at neck shoulder juncture.

 

[dnellans]

another rpr owner with what appears to be .040 freebore. not awesome

 

[Dgd6mm]

another rpr owner with what appears to be .040 freebore. not awesome

WOW, that is short.

 

[dnellans]

WOW, that is short.

108 eld’s have to be at 2.59-2.6 COAL to get off the lands. would be fine for a 70gr bullet but for what most of us shoot it’s silliness. nice forum member here is selling me a few 105 hybrids to see if getting a bit further out with those makes the gun useable. also have some smk 107’s en route

 

[JaoeyP]

Has any body who is having this problem called Ruger? I would think they'd take the rifle back under warranty if it won't chamber factory ammo.

 

[dnellans]

Not yet, but if I can't make it shoot hand loads then I will give them some guff. I figure what do they care if its got 200 rounds down the pipe versus 100 at this point if I'm going to have to explain to them its all out of sorts