RAR Feeding Issues

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RAR Feeding Issues

Postby Siringo » Tue Oct 16, 2018 4:50 pm

I purchased a RAR from Randy's a year or so ago for the sole purpose to be able to play around with heavy lead flat nose bullets. The Twist of 1/16 will work up to a 500 grain round nose. However, I found that feeding from the magazine the flat nose or long round nose would not feed well. Usually bumping into the chamber mouth and requiring a little wiggling of the bolt to get them to go in. It would feed pointed bullets all day long. Anyone have any experience with this in the RAR?
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Re: RAR Feeding Issues

Postby Al in Mi » Wed Oct 17, 2018 4:35 am

I don't have a RAR so grabbing at straws here, but you might need to make a feed ramp at the front of the mag like they had to do for the 45 Raptor in AR10's to feed the 240gr XTP mags. That ramp also served as a spacer to keep those short rounds from jacking forward in recoil. Feed lips needed to be cut back on those mags, worked flawlessly when I had mine. For the RAR it would be a single dish, but you get the concept.

My winter project was going to be a 450 bolt gun set up for cast so be following closely.

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Re: RAR Feeding Issues

Postby Radioactiveman » Wed Oct 17, 2018 6:13 am

I do have the same problem and that is the reason, why my RARR is back at the dealer for revision right now.

I made some loads with the Sierra 8830, which is a flat nosed bullet, and it fed horribly in my RARR.
Only pointed bullets feed properly, even the open-tipped Barnes 275gn got frequently stucked.
Both bullets incure severe deformation of the tip when they jam.
And also the pointed bullets (Hornady ftx) receive scratches, like chatter marks, when once fed. The chatter marks even on the factory ammo was the determining factor for me that there must be something wrong with the rifle itself.

But I did try several approaches to make it going. First I tightened the stock screws to reduce the distance between the mag and the feeding ramp and then shortened the magazin lips.
Both gave a minor improvement but still far from satisfying.
Of course i also played around with seating depth, but that made no difference at all.

Not sure if i got a lemon here, or if the rifle genuinely can't handle flat nosed bullets.
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Re: RAR Feeding Issues

Postby Siringo » Wed Oct 17, 2018 7:43 am

The RAR magazine will accommodate an AOL of at least 2.8 inches. So there is at least 0.6 inches of slop. Another issue, all RAR are like this, is the barrel face is flat. It is not coned like so many other bolt actions. The cartridge being fed is being pushed into the half inch hole and has a long way to go, in comparison to an AR. It will feed factory ammo fine, but departing from the bullet profile used in factory rounds causes the problems. I contemplated adding a radius to the rear of the barrel, but I am concerned about removing support of the cartridge case at the web.

The feed angle works OK for cartridges of factory length. Once the length gets longer, the nose of the bullet will hit the upper part of the barrel before it pops loose from the magazine. I bought a spare magazine and shorted the feed lips, but that didn't work as the cartridge was really unsupported and went in all directions. An option would be to modify the feed ramp on the receiver. I have two other short action RAR's (308 and 223) and it sure looks like the feed ramps are identical to the 450. I can understand from the manufacturing standpoint that Ruger would not cut a special ramp just for the 450, as one single receiver is used for many calibers. But the feed ramp could be modified to emulate the AR (mine will feed flat nose 405's all day long) seems to be the route to go. To me, the angle of approach into the chamber is to steep. There is a "U" notch cut into the ramp that does not match the profile/diameter of the 450 case. Widening that notch would lower the entrance angle.
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Re: RAR Feeding Issues

Postby Al in Mi » Wed Oct 17, 2018 8:20 am

yeah that ramp idea won't work if it's hitting the top of the chamber. almost sounding like you'd need to close up those feedlips to lower the angle, not quite sure how'd you'd go about that on a plastic mag
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Re: RAR Feeding Issues

Postby Siringo » Wed Oct 17, 2018 12:32 pm

Ali - on the top of the feed ramp (12:00) is a "u" shape cut. A 308 or 223 easily nestles in it. The 450, because the case diameter is a little larger than the 308, rides higher on the edges of the cut. Sorry, but I can not post pictures. Rather than changing anything with the ramp angle, the "U" would be relieved so the case would sit lower and present a narrower angle into the chamber. While this is an exaggeration, the difference would be an entry angle of 30 degrees versus 45 degrees. The "U" shape should be 0.500 rather than 0.470. Just thinking out loud!
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Re: RAR Feeding Issues

Postby Radioactiveman » Thu Oct 18, 2018 2:32 pm

Al in Mi wrote:yeah that ramp idea won't work if it's hitting the top of the chamber. almost sounding like you'd need to close up those feedlips to lower the angle, not quite sure how'd you'd go about that on a plastic mag

Don't you mean opening up the feedlips? I feel like we need to get the round loose earlier in the pushing process, tightening the feedlips should result in even later release of the round and also holding them down deeper in the mag which possibly steepens the angle even more?!

Siringo wrote:Ali - on the top of the feed ramp (12:00) is a "u" shape cut. A 308 or 223 easily nestles in it. The 450, because the case diameter is a little larger than the 308, rides higher on the edges of the cut. Sorry, but I can not post pictures. Rather than changing anything with the ramp angle, the "U" would be relieved so the case would sit lower and present a narrower angle into the chamber. While this is an exaggeration, the difference would be an entry angle of 30 degrees versus 45 degrees. The "U" shape should be 0.500 rather than 0.470. Just thinking out loud!


Modifying the feed ramp sounds promising, but also hard to execute.
I will first try the magpul stock which i like anyway. I hope maybe because of the different magazine there will be an improvement. I can still try to modify the feed ramp when the stock replacement doesn't work out.
Please keep me up to date when you try modifying the feed ramp.
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Re: RAR Feeding Issues

Postby Tripplebeards » Wed Jan 16, 2019 5:55 pm

I’m a little late to the party but you need to seat your cast bullets deeper. I have no problems feeding a lee 300 grain flat nose through my Ruger American loaded at 2.055” or shorter. Any longer and they jam. I made some test dummy bullets at various lengths and cycled them to see what worked and what doesn’t.

Check out my post ...need help with first time crimping the 450BM and you’ll see what I mean. I have pics posted. Best groups came from a stout load of 35.5 grains of H110 with a muzzle velocity of 2070fps.

Exit...mine is now not wanting to feed the last bullet in the Magazine. I believe it’s the spring in the magazine causing some of the issues. I’m going to try a more tapered flat nose bullet. The lee 300FN is not for the RAR unless you want to feed them like a single shot. It basically kicks the bullet up to high off the ramp and catches on the top of the action. Guess I could mess around modifying my magazine but all it takes is one time to jam when I’m shooting at a big buck to tell myself I told you so. Pick another cast bullet with a tapered nose.
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