FLASH HOLE PREP

[300ulta210]

I just read where someone bevels the flash hole on both sides,they stated that by doing so it would lower the E.S. and S.D. How many of you guys debur and bevel the flash hole on both sides? I always clean out my primer pockets and debur the flash hole from the inside only. What method do you use?

 

[Preacher]

Wonder what kind of a tool thats called, that does a bevel on the outside..
There is no burr there so I wonder why someone would even bother to do it..

 

[300ulta210]

I read an article on the home page of this site well in the guns of the week thread, it was the 7mm wsm the gun that shot a 10 shot group at around 5 to 6 inches at 1000 yrds off of bipods his name I believe was rich or rick can't remember which anyway he said it tapers the flash hole so the primer detination would be more uniform . One of those things that just makes you wonder.

 

[Preacher]

Neither of my K&M tools will allow that to happen, they won't go in far enough...

 

[btm_54]

Neither of my K&M tools will allow that to happen, they won't go in far enough...

I think my C&H tool could do inside and outside.
If you wanted to.
http://www.ch4d.com/ is the site that supplys them.

 

[bheadboy]

R. W. Hart has a tool that will do both inside and outside although i have never done the outside.

Bob

 

[cliffy]

I clean-out the rifle's primer pocket and debur the flash hole with a #46 drill bit. I hesitate to widen the primer pocket in any way, except for Korean PMC brass! A tight fit of primers is essential! Loose Pocket: Crush and Throw Away the otherwise valuable Brass vessel . . . Cliffy

 

[Gearheadpyro]

I use the Sinclair Gen II flash hole deburring tool on the inside, and the RCBS Flash hole tool just enough to chamfer the edge on the outside. Might be slightly overkill, but I'm using Winchester brass and the burrs when I got it were pretty bad. Shoots well enough now though.

 

[Ozzyshooter]

I have a Lyman primer pocket uniformer that puts a small chamfer around the flash hole at a shallow angle, I use the same tool as a pocket cleaner after every firing. Seems to work well enough.

 

[cliffy]

Take Care! Flash Holes are to remain as small as credible. BEFORE BORING OUT a primer hole, take note of WHY the manufacturer made it that size. If you can see through it, it's big enough. I fell into the trap of reaming flash holes much to my shagren. I've since learned that primer flash holes are PLENTY BIG to begin with . . . cliffy

 

[McFox]

I just ran a test on the influence of flash hole sizes on RWS .222 brass. The come with a 1.6mm hole. For comparison I opened up the fash hole to 2mm on 25 cases. Then loaded these 25 and 25 which were unpreped with the same load. NO EFFECT WHATSOEVER! Both were dead accurate with the same POI.

 

[queen_stick]

I just ran a test on the influence of flash hole sizes on RWS .222 brass. The come with a 1.6mm hole. For comparison I opened up the fash hole to 2mm on 25 cases. Then loaded these 25 and 25 which were unpreped with the same load. NO EFFECT WHATSOEVER! Both were dead accurate with the same POI.

That's an interesting test with interesting results. What range were you shooting? in a 222 cal rifle, you probably weren't shooting long range. I'm curious if this test was done at long range, if any vertical would show up?

I guess one way to determine that is to shoot this test over a chronograph... did you do that?

 

[McFox]

I was shooting at 100m. The groups with this ammo are 10-13mm at this distance. I don't have a chrono available.

 

[cliffy]

I have learn the HARDWAY that primer holes are BIG enough, yet a Number 46 drill bit can clean-up trashy "PUNCHED" holes, since Lapua and Norma drill their holes about #46 size. Cliffy

 

[Joe O]

Sinclair has this tool which cleans and sizes the flash hole to .081

http://www.sinclairintl.com/product/13604/Flash-Hole-Deburring-Tools