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March 31st, 2021

How to Create A Dummy Round to Aid Barrel Chambering

Gre Tannel GreTan, Gre-Tan Rifles dummy round chambering gunsmith reamer chamber

How and Why to Create a Dummy Round
When you have a new custom rifle built, or a new barrel fitted to an existing rifle, it makes sense to create a dummy round. This should have your preferred brass and bullet types, with the bullet positioned at optimal seating depth. A proper dummy round helps the gunsmith set the freebore correctly for your cartridge, and also ensure the proper chamber dimensions.

Respected machinist, tool-maker, and gunsmith Greg Tannel of Gre-Tan Rifles explains: “I use the dummy round as a gauge to finish cut the neck diameter and throat length and diameter so you have [optimal] clearance on the loaded neck and the ogive of the bullet just touches the rifling.” He recommends setting bullet so the full diameter is just forward of the case’s neck-shoulder junction. “From there”, Greg says, “I can build you the chamber you want… with all the proper clearances”.

Greg Tannel has created a very helpful video showing how to create a dummy round. Greg explains how to measure and assemble the dummy and how it will be used during the barrel chambering process. Greg notes — the dummy round should have NO Primer and No powder. We strongly recommend that every rifle shooter watch this video. Even if you won’t need a new barrel any time soon, you can learn important things about freebore, leade, and chamber geometry.

Must Watch Video — This has been viewed over 764,000 times on YouTube:

This has been a very popular video, with 764,000 views! Here are actual YouTube comments:

That is the best explanation I’ve ever seen. Thank you sir. — P. Pablo

Nice video. You do a very good job of making this easy for new reloaders to understand. I sure wish things like this were available when I started reloading and having custom rifles built. Once again, great job, and your work speaks for itself. — Brandon K.

Beautiful job explaining chambering clearances. — D. Giorgi

Another Cool Tool — The Stub Gauge

When you have your gunsmith chamber your barrel, you can also have him create a Stub Gauge, i.e. a cast-off barrel section chambered like your actual barrel. The stub gauge lets you measure the original length to lands and freebore when your barrel was new. This gives you a baseline to accurately assess how far your throat erodes with use. Of course, as the throat wears, to get true length-to-lands dimension, you need take your measurement using your actual barrel. The barrel stub gauge helps you set the initial bullet seating depth. Seating depth is then adjusted accordingly, based on observed throat erosion, or your preferred seating depth.

Stub Gauge Gunsmithing chamber gage model barrel

Permalink - Articles, - Videos, Bullets, Brass, Ammo, Tech Tip No Comments »
August 17th, 2019

Cure Primer Cratering — Greg Tannel Firing Pin Bushing Service

Crater moon primers greg tannel bushing firing pinCraters may look interesting on the moon, but you don’t want to see them on your primers. Certain mechanical issues that cause primer craters can also cause primer piercing — a serious safety problem that needs to be addressed. If you have a gun that is cratering primers (even at moderate pressure levels), there is a solution that works with many rifles — send your bolt to Greg Tannel to have the firing pin hole bushed.

Shooters who convert factory actions to run 6BRs, 6PPCs or other high-pressure cartridges should consider having the firing pin bushed. These modern cartridges like to run at high pressures. When running stout loads, you can get cratering caused by primer flow around the firing pin hole in the bolt face. The reason is a little complicated, but basically the larger the hole, the less hydraulic pressure is required to crater the primer.

A limited amount of cratering is normally not a big issue, but you can reduce the problem significantly by having a smith fit a bushing in the firing pin hole. In addition to reduced cratering, bushing the firing pin often produces more consistent ignition.

CLICK HERE for Gre-Tan Firing Pin Hole Bushing Service INFO »

This is a highly recommended procedure that our editors have had done to their own rifles. Greg Tannel (Gre-Tan Rifles) is an expert at this procedure, and he does excellent work on a wide variety of bolts. Current price for a bushing job, which includes turning the firing pin to .062″, is $92.00, or $100.00 with USPS Priority Mail return shipping.

If you have a factory rifle, a bushed firing pin is the way to go if you are shooting the high-pressure cartridges such as 6PPC, 6BR, 6-6.5×47 and 6.5×47. This is one of the most cost-effective and beneficial upgrades you can do to your factory rifle. For more info on the Firing Pin Bushing process, visit GreTanRifles.com, or email greg [at] gretanrifles.com. After clicking the link for GreTanRifles.com, Click on “Services” > “Shop Services” and you’ll see a listing for “Bush Firing Pin Hole & Turn Pin”. CLICK that Box.

Gre-Tan Rifles firing pin bushingFiring Pin Hole Bushing by Greg Tannel

Work Done: Bush firing pin hole and turn pin
Functions: Fixes your cratering and piercing problems
Price: $92.00 + $8.00 return shipping
Total Price: $100.00

Actions for which Bushing is Offered: Remington, Winchester, Savage multi-piece pin, Sako, Kimber, Nesika, Stiller, BAT Machine, Kelbly, Lawton, Surgeon, Borden, Wichita, Hall, Ruger, Howa, Weatherby, Dakota, Pacific Tool, Phoenix, and Defiant bolt action rifle or pistol.

Actions for which Bushing is NOT Available: Case hardened receivers, ARs, Accuracy International (AI), Barnard, Big Horn, Cooper, Desert Tactical Arms, Kimber, Rosenthal, New Savage single piece pin, Rim fires, Falling block, Break open, Lever, Pump rifles, 1903-A3, CZ, Mauser.

How to send your bolt in to be bushed:
Send your bolt and firing pin assembly via snail mail, priority mail, or UPS. Please do not use FEDEX as it sometimes has delivery delays.Include your name, phone number, and return shipping address, and a note as to what you want done. Pack your bolt carefully and ship to: Gre’-Tan Rifles, 24005 Hwy. 13, Rifle CO 81650.

Due to the high volume of work, turn-around time for bolt bushing jobs can be 12 weeks (though it usually is faster). Customers can pay by check, money order, or credit card. For more information visit GretanRifles.com.

Permalink Gunsmithing, Tech Tip No Comments »
November 5th, 2017

TECH TIP: Beat Primer Craters by Bushing Firing Pin Holes

Greg Tannel Gre-Ten Bush Bushing Bolt Firing Pin Hole

Crater moon primers greg tannel bushing firing pinCraters may look interesting on the moon, but you don’t want to see them on your primers. Certain mechanical issues that cause primer craters can also cause primer piercing — a serious safety problem that needs to be addressed. If you have a gun that is cratering primers (even at moderate pressure levels), there is a solution that works with many rifles — send your bolt to Greg Tannel to have the firing pin hole bushed. CLICK HERE.

Shooters who convert factory actions to run 6BRs, 6PPCs or other high-pressure cartridges should consider having the firing pin bushed. These modern cartridges like to run at high pressures. When running stout loads, you can get cratering caused by primer flow around the firing pin hole in the bolt face. The reason is a little complicated, but basically the larger the hole, the less hydraulic pressure is required to crater the primer. A limited amount of cratering is normally not a big issue, but you can reduce the problem significantly by having a smith fit a bushing in the firing pin hole. In addition to reduced cratering, bushing the firing pin often produces more consistent ignition.

CLICK HERE for Gre-Tan Firing Pin Bushing Service INFO »

This is a highly recommended procedure that our editors have had done to their own rifles. Greg Tannel (Gre-Tan Rifles) is an expert at this procedure, and he does excellent work on a wide variety of bolts. Current price for a bushing job, which includes turning the firing pin to .062″, is $80.00, or $88.00 with USPS Priority Mail return shipping.

If you have a factory rifle, a bushed firing pin is the way to go if you are shooting the high-pressure cartridges such as 6PPC, 6BR, 6-6.5×47 and 6.5×47. This is one of the most cost-effective and beneficial upgrades you can do to your factory rifle. For more info on the Firing Pin Bushing process, visit GreTanRifles.com, or email greg [at] gretanrifles.com. (After clicking the link for GreTanRifles.com, Click on “Services” > “Shop Services” > “Bolt Work”, and you’ll see, in the lower left, a listing for “Bush Firing Pin Hole & Turn Pin”. Click on that box.)

Gre-Tan Rifles firing pin bushingFiring Pin Hole Bushing by Greg Tannel

Work Done: Bush firing pin hole and turn pin.
Functions: Fixes your cratering and piercing problems.
Price: $80.00 + $8.00 return shipping
Total Price: $88.00

Actions for which Bushing is Offered: Remington, Winchester, Savage multi-piece pin, Sako, Kimber, Nesika, Stiller, BAT Machine, Kelbly, Lawton, Surgeon, Borden, Wichita, Hall, Ruger, Howa, Weatherby, Dakota, Pacific Tool, Phoenix, and Defiant bolt action rifle or pistol.

Actions for which Bushing is NOT Available: Case hardened receivers, ARs, Accuracy International (AI), Barnard, Big Horn, Cooper, Desert Tactical Arms, Kimber, Rosenthal, New Savage single piece pin, Rim fires, Falling block, Break open, Lever, Pump rifles, 1903-A3, CZ, Mauser.

How to send your bolt in to be bushed:
You can send your bolt snail mail, priority mail, or UPS (Please do not use FEDEX as it sometimes has delivery delays). Pack your bolt carefully and ship to: Gre’-Tan Rifles, 24005 Hwy. 13, Rifle CO 81650. Please include your name, phone number, and return shipping address.

Due to the high volume of work, turn around is 5 to 8 weeks on bushing a bolt. Three or more bolts will be sent back to you UPS and we will have to calculate shipping. We can overnight them at your expense. You can pay by check, money order, or credit card. For more information visit GretanRifles.com.

Permalink Gunsmithing, Tech Tip No Comments »
October 5th, 2014

Cure Craters With a Gre-Tan Firing Pin Bushing Job

Crater moon primers greg tannel bushing firing pinCraters may look interesting on the moon, but you don’t want to see them on your primers. Certain mechanical issues that cause primer craters can also cause primer piercing — a serious safety problem that needs to be addressed. If you have a gun that is cratering primers (even at moderate pressure levels), there is a solution that works with many rifles — send your bolt to Greg Tannel to have the firing pin hole bushed.

Shooters who convert factory actions to run 6BRs, 6PPCs or other high-pressure cartridges should consider having the firing pin bushed. These modern cartridges like to run at high pressures. When running stout loads, you can get cratering caused by primer flow around the firing pin hole in the bolt face. The reason is a little complicated, but basically the larger the hole, the less hydraulic pressure is required to crater the primer. A limited amount of cratering is normally not a big issue, but you can reduce the problem significantly by having a smith fit a bushing in the firing pin hole. In addition to reduced cratering, bushing the firing pin often produces more consistent ignition.

This is a highly recommended procedure that our editors have had done to their own rifles. Greg Tannel (Gre-Tan Rifles) is an expert at this procedure, and his turnaround time is fast — usually 2-3 days (shop time). Current price for a bushing job, which includes turning the firing pin to .062″, is $87.00 including USPS Priority Mail return shipping.

Gre-Tan Rifles firing pin bushing

If you have a factory rifle, a bushed firing pin is the way to go if you are shooting the high-pressure cartridges such as 6PPC, 6BR, 6-6.5×47 and 6.5×47. This is one of the most cost-effective and beneficial upgrades you can do to your factory rifle. For more info on the Firing Pin Bushing process, visit GreTanRifles.com, or email greg [at] gretanrifles.com. (After clicking the link for GreTanRifles.com, Click on “Services” > “Shop Services” > “Bolt Work”, and you’ll see a listing for “Bush Firing Pin Hole & Turn Pin”. Select “View Details”.)

Gre-Tan Rifles firing pin bushingFiring Pin Hole Bushing by Greg Tannel

Work Done: Bush firing pin hole and turn pin.
Functions: Fixes your cratering and piercing problems.
Price: $80.00 + $7.00 return shipping
Total Price: $87.00

Actions for which Bushing is Offered: Remington, Winchester, Savage, Sako, Kimber, Cooper, Nesika, Stiller, Bat, Kelbly, Lawton, Surgeon, Borden, Wichita, Hall, CZ, Ruger, Mauser, Howa, Weatherby, Dakota, Pacific Tool, Phoenix, RPA Quadlite, and Defiant bolt action rifle or pistol. Note: There may be extra tooling charges for case-hardened style bolts (Mauser, CZ, and similar) .

Actions for which Bushing is NOT Available: ARs, Accuracy International, Desert Tactical Arms, Big Horn, Rim fires, Falling block, Break open, Lever, Pump rifles.

How to send your bolt in to be bushed:
You can send your bolt snail mail, priority mail, UPS, Fed-Ex. What ever you prefer. Please include your name, phone number, and return shipping address. Turn around is normally 1 to 3 days shop time (plus shipping time). We usually do them the day that we get them in. Total cost is $87.00 for one bolt or $167.00 for two (this includes return shipping, priority mail.) Three or more will be sent back to you UPS and we will have to calculate extra shipping. We can overnight them at your expense. Check, money order, or credit card is fine with us.

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