As an Amazon Associate, this site earns a commission from Amazon sales.

April 23rd, 2020

Rebating Case Rims Let You Shoot BR Brass with PPC Action

30BR 6 PPC rim rebated Butch Lambert

Many short-range Benchresters have thought about converting their 6 PPC to shoot a 30BR for score matches, or a Dasher for mid-range (or even 1000-yard) games. That way you have a rifle that does double duty, giving you the most bang for your buck. Though an action with a PPC bolt won’t normally work with 30BR/6BR/Dasher cases with their larger .308-class rim (0.4728″ diameter), there is a pretty easy solution that allows you to cycle these bigger cartridges with a 6PPC-style bolt (designed to fit .220 Russian rims).

“Rebating case rims … lets you shoot a 30BR in score matches using your PPC action. All you need is a new barrel. This saves buying another bolt, receiver, or rifle.” — Butch Lambert

Butch Lambert of ShadeTree Engineering provided this tip. Butch notes that many 6 PPC benchrest group shooters also enjoy shooting in score matches. But to be really competitive in the BR for score game, that means shooting a 30BR, which has a wider, .308-class rim (0.4728″ diameter). Likewise, if you want to compete in 600-yard registered BR events or in varmint matches, you probably want to run a bigger case, such as the 6BR, 6mm Dasher, or 6-6.5×47. Those cartridges also have the larger 0.4728″ rims.

30Br Butch Lambers 6 PPC

Cutting Head for Rebating Rims
To convert a PPC-boltface action to shoot the bigger cases you can spend a ton of money and buy a new bolt. That can cost hundreds of dollars. The simpler solution is to turn down the diameter of the larger cases on a lathe. Butch explains: “We’ve seen plenty of interest in rebating case rims. This lets you shoot a 30BR in score matches using your PPC action. All you need is a new barrel. This saves buying another bolt, receiver, or rifle if you have a PPC boltface. Anyone who has access to a lathe can do this job pretty easily. Yesterday I turned 150 case in about an hour.” At right is the lathe form tool Butch uses to rebate the case rims.

Permalink Gear Review, Gunsmithing, Tech Tip 1 Comment »
March 21st, 2017

The Amazing 30 Major — 6.5 Grendel Necked Up to .30 Caliber

30 Major 6.5 Grendel 30 caliber PPC

Sometimes everything comes together — a great barrel, the right load, good bullets, and, of course, a gifted trigger-puller. Check out this target from Forum member Mike Ezell. That’s five (5) shots at 100 yards from Mike’s 30 Major benchrest rifle. When this group was shot a while back, Mike reported: “I fired a few groups in the great weather. No surprises — it did VERY well! My little wildcat, the 30 Major, has always been a shooter. That target was not a fluke — I shot a few groups today and Agg’d a high One.” Mike is a Kentucky gunsmith who builds his own rifles.

30 Major is Based on 6.5 Grendel
What’s a “30 Major” you ask? This is Mike’s own wildcat, a 6.5 Grendel necked up to .30 caliber. Mike writes: “The 30 Major is essentially a .070″-long 30 PPC. With the great 6.5 Grendel brass available from Lapua, all you need to do is neck-up and turn the necks to prep the brass.” Mike says it is very much like a 30 BR, but you just start with 6.5 Grendel brass instead of 6mmBR brass.

The cartridge has one major benefit — it utilizes a PPC-diameter bolt face. That makes it easy to convert your group-shooting 6 PPC to shoot score with .30-cal bullets. Mike explains: “If you have a PPC, to shoot score, all you have to do is chamber up a [.30 caliber] barrel and screw it on your PPC.”

From 7.62×39 Russian to 30 Major — Full Circle

Arms expert Neil Gibson has an interesting perspective on the lineage of the 30 Major. He reminds us that this wildcat has returned to its roots: “Start off with the 7.62×39 Russian [cartridge]. The Russians then modify it, necking it down to .223 for deer hunting. The U.S. benchrest guys then modify that, necking it up to 6mm and blowing the case out making the 6mm PPC. Someone takes that case, necks it out to 6.5 mm, making the 6.5 PPC. Alexander Arms takes that and makes the 6.5 Grendel. Then finally Mike Ezell takes the Grendel and necks it up to 30 caliber, making the 30 Major. From 30 caliber, back to 30 caliber. OK, the original uses .31 caliber bullets, but the bore is still .300. Talk about almost coming round full circle!”

7.62×39 Russian
.220 Russian
6mm PPC
6.5 PPC
6.5 Grendel
30 Major

The 7.62×39 Russian was the Grand-Daddy of the 30 Major…
7.62x39 Russian Kalashnikov 30 Major 6.5 Grendel

Great Accuracy Restored after Solving Mystery Problem
To get his 30 Major rig shooting this well, Mike had to solve a mysterious problem that cropped up last year. Mike explains: “Two years running, I have finished in the top 15 in IBS points shooting [the 30 Major], but last year’s benchrest season was tough.” Mike was having some accuracy issues that defied explanation. But he figured it out: “The front action screw was bottoming out against the barrel extension – just barely. A simple fix brought the gun back to life. It’s a Stiller Viper Drop Port. The action is screwed and glued into the stock, so I was a bit surprised … especially after having checked for [that issue] while looking for the problem. I’m just glad to have found the trouble so I can begin to re-instill some confidence in the gun and myself, after last year.”

Permalink Bullets, Brass, Ammo, Reloading 10 Comments »
June 1st, 2011

New Lapua 220 Russian Brass — Thicker Necks?

220 Russian brass lapuaJackie Schmidt, posting on Benchrest Central, observed that there may have been some production changes with Lapua 220 Russian brass. This brass is commonly used as the parent case for fire-forming 6 PPC cases. The newer 220 Russian brass has slightly thicker neckwalls, and, according to Jackie, the new brass is more consistent in overall neckwall thickness.

Jackie writes: “I have not made any new PPC cases in a while. But I finally used up all of my older 220 Russian brass, and just bought 500 new cases, in the blue plastic boxes. The necks are thicker. By at least .0008 (eight ten-thousandths). That is right at .0015 on diameter. I am getting neck-wall thickness of .0142″ on the old cases, .0150″ on the new cases. I [fire-formed] two cases, and seated a Flat Base Ultra bullet in each. The old case, with a seated bullet and non-neck-turned case, measures .2708″ average. By contrast, the new case, with a seated bullet in an unturned neck, measures .2722″ average. That is, on average, about .0015 difference in the diameter of a seated round.”

“Anybody else notice this? I guess the main reason I did the measuring is that I am thinking of having a ‘no-neck turn’ reamer ground. With this new brass, .0274″ would be the minimum. The new brass is a tad better in overall [neck]-wall thickness variation.” — Jackie

What does Lapua say? We’ve sent inquiries to Lapua’s USA tech representatives. We hope to have a response soon.

Permalink Bullets, Brass, Ammo 1 Comment »
July 25th, 2008

McGowin Shoots 300-yard Record Group

Shooting in the Unlimited (rail gun) class, James “Jim” McGowin shot a 0.355″ 5-shot group at 300 yards. This has now been officially “certified” as a new NBRSA record. McGowin’s group beat the previous 0.373″ shot by Art Freund in 1981. McGowin was shooting the 6mm Beggs cartridge in a match in St. Louis, MO. For his record group, Jim used his own 63 grain BT bullet, a 7.5 ogive made on J-4 .750 jackets in a Niemi die.

The 6mm Beggs cartridge is basically a 220 Russian necked up to 6mm, with a very small modification of the radius at the neck-shoulder junction. (Gene Beggs added a tighter radius to reduce case lengthening on repeated firings.) The 6mm Beggs, and its smaller cousin, the 220 Beggs, have slightly less capacity than a fire-formed PPC case. However, in a good BR gun, the “raw accuracy” of the Beggs’ cartridges can rival that of a 6 PPC. Indeed a standard, unmodified 220 Russian is competitive in the 100/200 yard BR game. Lou Murdica, a top shooter on the short-range BR circuit, has won many matches with a “plain-jane” unmodified 220 Russian.

Permalink Competition No Comments »