So I have a savage ftr in 308 with a 30 inch barrel and so far have basically just shot federal 168 factory ammo and it has been impressives. So I am new to reloading and have federal match casings that are identical same headspace and same overall lenth with 168s that all weight the same. So I load up groups of 10 in different powder grains at 42.8, 42.6, 42.3, 42.0, 41.7 grains. The only difference is out of the 10 I load up at each weight is. I I drill the flash hole on 5 of each at each grain weight so iam shooting 10 at each weight 5 with the flash holes drilled and 5 not drilled.mi have no chrono cause I spent about 5 grand already and am way over budget for the year. I was actually expecting the flash hole drilled to be more accurate and the were awful could not hardly keep them below 3 moa while the I drilled were .5 or less basically 1 whalers. Iam thinking drilling th flasholes are giving very high pressures to start and burning up to quickly to push the bullet out the barrel . Iam a newbie so any help would appreciated if you need more info just pm me
Drilling the flash hole
- Thread starter Wjesswheel
- Start date
Corey Schwanz
Site $$ Sponsor
What did you use to drill them and how big? You don't want to enlarge them anymore than necessary. A deburring tool can knock off burrs around the interior of the flash hole and make the flash more consistent but you shouldn't be changing the actual size of the hole.
Wjesswheel,
As the other guys have mentioned, opening up flash holes (unless it's being done for a very specific application, and this ISN'T it) is generally a bad idea. You're actually going the wrong direction here; among those cartridges that were designed specifically from the ground up as "accuracy cartridges", many use a smaller diameter flash hole than regular cases. In our line, the 220 Russian, the 6mmBR, the 6.5x47L and the 308 Win Palma cases all use a 1.5mm or .060" flash hole, where the normal size is .080" or 2mm for our other cases. That .080" diameter, incidentally, is pretty much the industry standard. As Preacher noted, there is generally a loss of accuracy when these holes are opened up too much. Don't know that that was specifically the cause of his inaccuracy problems, but clearly, it didn't help.
You mention being new to this. I think there's probably other areas, both on the reloading bench and the firing line, that will benefit from more attention that's being misspent on drilling flash holes.
As the other guys have mentioned, opening up flash holes (unless it's being done for a very specific application, and this ISN'T it) is generally a bad idea. You're actually going the wrong direction here; among those cartridges that were designed specifically from the ground up as "accuracy cartridges", many use a smaller diameter flash hole than regular cases. In our line, the 220 Russian, the 6mmBR, the 6.5x47L and the 308 Win Palma cases all use a 1.5mm or .060" flash hole, where the normal size is .080" or 2mm for our other cases. That .080" diameter, incidentally, is pretty much the industry standard. As Preacher noted, there is generally a loss of accuracy when these holes are opened up too much. Don't know that that was specifically the cause of his inaccuracy problems, but clearly, it didn't help.
You mention being new to this. I think there's probably other areas, both on the reloading bench and the firing line, that will benefit from more attention that's being misspent on drilling flash holes.
Chappy said:
Not a big deal if he is using large rifle primers.... An .080" flash hole with a small rifle primer is going to be less than optimum...
Some time ago when I was playing with a 22 cheetah I was forming brass from small rifle primer cases... At that time some guys in the shop were keen on running drill bits into their brass to "uniform" the flash hole diameter and in this case someone opened up 20 or so of my cases to aprox .080... After I had told him I was not interested in ruining my cases I decided to try them anyways. And dismal would be putting it lightly lol.
My own personal testing has shown me that in most cases , running a bit into your flash hole should be saved for cases that have no flash hole to begin with.
Keith Glasscock
Gold $$ Contributor
Using a drill bit as a reamer doesn't work real well. Holes get tapered, elongated, and much bigger than intended on a regular basis.
I have been uniforming flash holes long before Sinclairs offered their flash hole tool. I respectfully suggest that if you don't have a copy of Warren Pages book " The Accurate Rifle " 1973 then obtain a copy. I don't have a copy to hand so I cannot cite the exact page in which Mr Page says " uniform your flash holes ."
Before I continue, there was an excellent article on this site about a Gentleman of some repute who explained within the article how he found that the discrepancies in flash hole diameter was one of the causes of his errors. This same Gentleman also explained how he took a large number of his preferred cases to a local machine shop and had the guy 'pin gauge' his flash holes, he was then able to determine the correct sized reamer to use to 'uniform his flash holes.' And if memory serves this same Gentleman was offering flash hole reamers well before Sinclairs. Unfortunately after extensive searching I cannot locate the article to direct you to. But I do recall how this same chap shoots all his loads over a chrono which allows him to isolate those cases which do not meet his criteria.
And unfortunately I cannot recall his name. Perhaps some of the more experienced forum members could assist in locating this article.
Now before any body jumps on me and says drilling and reaming are not the same , well actually they are. One can use a 4 flute chucking reamer or a standard twist drill, drills are a problem as they are rarely made in the sizes required. Letter & Number drills are close but usually fall short. The only way is to use a 4 flute chucking reamer. I use TRI-ANGLE USA purchased online from Discount tools in California. http://www.discount-tools.com/
I use a block of aluminium ( sorry aluminum ) 3 " x 2 " x 3/4" into which I cut a 7/8 x 14 thread, into which is screwed a Redding .308 body die. The block and die is turned upside down so the die entrance is uppermost and then placed into a machine vice and the block is leveled.
The machine vice is bolted down to the mill bed and aligned under the chuck , a parallel 4 flute reamer is inserted into a Eclipse Pin Chuck.Drop a case into the body die, lower the chuck , done . The case rarely spins in the die , it is not in there long enough to cause issues.
Drill bits work fine but not in a hand held Black & Decker. I have used 2.1mm twist drills which are 0.0826" when I had lent out my reamers or broke them and was waiting for more to arrive.
If you care to do the test , take 20 new cases , uniform the flash holes of 10 , load the 20 cases with the same components , then go shoot them over a chrono , I will be very surprised if the SD & ES of the loads with the uniformed flash holes does not improve.
And if you want to take the test even further use the same cases,powder and projectiles & seating depth but change the primers.
You just may be surprised to find the primers which you thought were the bees knees, don't give the results you thought you were getting. If you have never uniformed your flash holes , do so , and then switch primers and repeat the test over a chrono.
I did this test with every available primer, the BR primers were the worst, that is not to say BE primers are bad , just that they did not perform as I expected. RWS LR Primers gave the best SD & ES and are my go to primer , PMC Russians are right up there to.
I then got silly and reamed the flash holes to 0.0830" the results are attached ; I now ream all my flash holes 0.0830" , I have not any ISSUES with flash holes uniformed to 0.830" But I do have reamers in 0.820" / 0.825" & 0.830".
PIN GAUGE YOUR FLASH HOLES FIRST before doing any modification to them.
The string on the left was shot with 45.9 Grains Varget & 155 SMK's & RWS PRIMERS , the right string same, except powder charge was reduced to 45.5 grains Varget .
2934 2931
2941 2928
2923 2946
2935 2946
2966 2930
2962 2937
2971 2929
2956 2929
2943 2942
2955 2926
15.75 7.7 SD
2950.2 2934.4 AVE
48 20 ES
" Only Accurate Rifles, are interesting" Warren Page .
regards
Mike.
Before I continue, there was an excellent article on this site about a Gentleman of some repute who explained within the article how he found that the discrepancies in flash hole diameter was one of the causes of his errors. This same Gentleman also explained how he took a large number of his preferred cases to a local machine shop and had the guy 'pin gauge' his flash holes, he was then able to determine the correct sized reamer to use to 'uniform his flash holes.' And if memory serves this same Gentleman was offering flash hole reamers well before Sinclairs. Unfortunately after extensive searching I cannot locate the article to direct you to. But I do recall how this same chap shoots all his loads over a chrono which allows him to isolate those cases which do not meet his criteria.
And unfortunately I cannot recall his name. Perhaps some of the more experienced forum members could assist in locating this article.
Now before any body jumps on me and says drilling and reaming are not the same , well actually they are. One can use a 4 flute chucking reamer or a standard twist drill, drills are a problem as they are rarely made in the sizes required. Letter & Number drills are close but usually fall short. The only way is to use a 4 flute chucking reamer. I use TRI-ANGLE USA purchased online from Discount tools in California. http://www.discount-tools.com/
I use a block of aluminium ( sorry aluminum ) 3 " x 2 " x 3/4" into which I cut a 7/8 x 14 thread, into which is screwed a Redding .308 body die. The block and die is turned upside down so the die entrance is uppermost and then placed into a machine vice and the block is leveled.
The machine vice is bolted down to the mill bed and aligned under the chuck , a parallel 4 flute reamer is inserted into a Eclipse Pin Chuck.Drop a case into the body die, lower the chuck , done . The case rarely spins in the die , it is not in there long enough to cause issues.
Drill bits work fine but not in a hand held Black & Decker. I have used 2.1mm twist drills which are 0.0826" when I had lent out my reamers or broke them and was waiting for more to arrive.
If you care to do the test , take 20 new cases , uniform the flash holes of 10 , load the 20 cases with the same components , then go shoot them over a chrono , I will be very surprised if the SD & ES of the loads with the uniformed flash holes does not improve.
And if you want to take the test even further use the same cases,powder and projectiles & seating depth but change the primers.
You just may be surprised to find the primers which you thought were the bees knees, don't give the results you thought you were getting. If you have never uniformed your flash holes , do so , and then switch primers and repeat the test over a chrono.
I did this test with every available primer, the BR primers were the worst, that is not to say BE primers are bad , just that they did not perform as I expected. RWS LR Primers gave the best SD & ES and are my go to primer , PMC Russians are right up there to.
I then got silly and reamed the flash holes to 0.0830" the results are attached ; I now ream all my flash holes 0.0830" , I have not any ISSUES with flash holes uniformed to 0.830" But I do have reamers in 0.820" / 0.825" & 0.830".
PIN GAUGE YOUR FLASH HOLES FIRST before doing any modification to them.
The string on the left was shot with 45.9 Grains Varget & 155 SMK's & RWS PRIMERS , the right string same, except powder charge was reduced to 45.5 grains Varget .
2934 2931
2941 2928
2923 2946
2935 2946
2966 2930
2962 2937
2971 2929
2956 2929
2943 2942
2955 2926
15.75 7.7 SD
2950.2 2934.4 AVE
48 20 ES
" Only Accurate Rifles, are interesting" Warren Page .
regards
Mike.
memilanuk
Gold $$ Contributor
Very informative, Mike. I just might have to try that out myself (the testing part).
Was your data at the end there meant to show the improvement between consistent and inconsistent flash holes, or just a sample of what kind of numbers you get with your prepped brass?
Was your data at the end there meant to show the improvement between consistent and inconsistent flash holes, or just a sample of what kind of numbers you get with your prepped brass?
memilanuk said:
Memilanuk ,, those posted results are only 2 of approx 8 I did with primers , I wanted to see for myself what primer performance I would get with all available primers for my standard Palma load , a load which I have used with success for approx the last 15 years.
One could argue that every time you replace a barrel you should work up a new load , I agree , but experience has taught me that a .308 is a very forgiving cartridge to load for, in fact I use the same load for 4 different 155 grain match projectiles and the only thing that changes for all 4 bullets is the seat depth. With a new barrel I use my standard load always.So the idea was to find out which primer gave the best SD & ES , the only case prep I do is to uniform the flash holes, I don't neck turn nor batch weigh cases but have recently begun neck annealing. I recall being told many years ago that the 2 most important things for accurate ammo for LR was to find a primer that gives good figures and consistent neck tension , I have followed that advice and have enjoyed good match success.
Mike.
dmoran said:
Donovan , an erudite observation I agree entirely but you see unlike the US we down here are governed by a serious set of Match Rules , not all 155 match projectiles are approved for use, the Lap 155 Scenar being one such and we are restricted to 2 types of powder for use. 2208 ( Varget ) and 2206H ( H4895 ) I think 8208 may have been approved but I am not sure at present.
So you see , testing all available powders is not an option , if I had my way , all powders would be acceptable. I switched to 2206H about 2 years back, the main reason being, it burns cleaner than Varget , results have not changed hardly at all compared to Varget, just seating depth and there is only 0.5 grains of powder difference between my old Varget load and the load for 2206H.
Mike.
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