Throat reamer

[redneckdan]

Does anyone have a .30 cal throat reamer that they would consider loaning to me? thanks.

[smokemjoe]

I would pay rental also for one with 1/2 or 1 Deg. per side. Joe

[leftiye]

They's one on evilbay, maybe for about what rental might run. Sorry, I don't have one.

[Doughty]

Dan,

At a recent gunshow, I picked up what appears to be a new and unused Clymer .30 throating reamer. I don't know what actual size throat it cuts, as I have never used it and, since it's a five flute, I don't have the proper tool to measure it direct and, I'm too lazy to do the math. It looks like about a 3* leade, definitly not a .5*.

If you'll PM me with your mailing address I'll send it to you. After you're through, you could send it on to smokemjoe, if he wants it, and he could send it back to me.

[nvbirdman]

What a great bunch of guys we have on this forum.

[redneckdan]

PM sent. I'd be happy to pass it along to smokemjoe. I'm not picky about the angles, anything is better than what I have right now. I also have the equipment for measuring the reamer. thank you.

[Doughty]

Dan,

It's on the way by Priority Mail. Watch'ya makin?

[redneckdan]

working on a .300 whisper, del-ton upper. The stock throat is way too short, its set up for sierra 240gr condoms. Cast boolits have a more blunt profile. The goal is have the cartridge fill a standard magazine, instead of being a half inch short. I'm currently working with 155gr lee 7.62 and 170gr lee flat nose moulds. I'm working a 325 gr mould for this gun, the length of that boolit will be .150" short of the maxiumim length that the twist will stablize at sub sonic velocity. For cutting this mould, I'm combining the cherry and lathe bore methods, I'll explain in detail if it works.

[smokemjoe]

redneckdan: After you throat the barrel, Make a chamber cast and hopefully you can figure out the angle, I got some Swiss K31s that I would to throat, I am set up with 3 bump dies for 1 Deg., & a 1/2 deg. , Dont what to get any different angles or have to make more bump dies, Let me know what you come up with, Your all a great help. Unreal.Smokemjoe

[redneckdan]

so are you actually gonna change the angle of the front of the boolit with the dies? I don't quite understand the "bump die" concept. I'm gonna use precision gage blocks , v block and dial indicator to measure the reamer.

[smokemjoe]

A bump die is made from 7/8x14 stock. A hole is drill and reamed into it the size you need. Then after you throat the rifle you throat the die also. You make a push pin to push the bullet into the die and a ejector pin to kick the bullet out from the top. Then the bullet is the same size as the throat is in the barrel. That way you can seat the bullet out to fit the lead in the chamber. The bullet matchs the barrels throat. You have to take a loading press and make linkage fitted to the die. Dont let this get you all confused. Smokemjoe

[redneckdan]

makes sense, but does it actually improve accuracy?

[redneckdan]

I measured the reamer, it measured at just under 1* on the leade. I measured it by chucking it lightly in the lathe, using a dial indicator on the cross slide to measure rise over run and then did the trigonometry. I will throat my barrel and then do a chamber cast just to be sure. I'm also gonna make a reamer handle to go with the tool, long enough to do AR-15 barreled actions.

[Doughty]

What is the throat diameter?

[smokemjoe]

if thats a 30 cal. throater, Isnt the AR 15 a 224 cal. barrel.

[redneckdan]

don't worry man, its all a matter of applied force[smilie=1:



on the serious note. most ar-15s are .223 Mine is a .300 whisper. take a .223, shorten to .221 fireball and neck up to .30 cal. Balistic equivelent of a 7.62x39 or a .30-30 The big idea is to shoot super heavy boolits at sub sonic velocities. My twist is 1:7, look down the barrel and it has the appearence of a screw thread.


I'm probably gonna have to wait until I throat the barrel and chamber cast in order to measure the actual diameter.

[redneckdan]

Heres the reamer extension. The set screw for retaining the reamer is a 3mmx.5mm, sorry, it was all I had handy in the shop. I'm going to included the extension with a couple allen wrenches when I forward the reamer. The end of the extension is filed square to fit into a tap wrench.

http://i17.photobucket.com/albums/b77/redneckdan/IMGP2573-1.jpg

http://i17.photobucket.com/albums/b77/redneckdan/IMGP2576.jpg

[redneckdan]

I reamed my AR barrel night before last, went out and test shot it last evening. I throated the barrel for the longest and bluntest profile boolits that would fit in the magazine. I used 50/50 tap magic and Mobil 1 10w30 as a cutting fluid, worked like a charm and the finish was supurb. Didn't take more than 5-6 turns on the wrench and it was done. I test fired it last evening, the full length boolits worked great. The shorter boolits with a 2 ogive radius now sat about 3/8 of an inch off the lands but accuracy was actually better now than with the original throat. Who gets the reamer next?

[Doughty]

Dan,

Sounds like everything worked out good. What diameter are you sizing your bullets at?

I don't know if smokemjoe wants it or not. Let's wait a little and see if he or somebody else pipes up.

[redneckdan]

boolits are sizing at .310 right now. my actual bore diameter is .307, I need to get a smaller lee sizer in my next midway order.