Defiance Actions - Bolt Noses

[lazyMlazyK]

I'd like to build a PRS rifle one of these days, and have started doing some research. Can anyone educate me on the differences between these bolt noses? What are each of them typically used for, and why? I'm assuming the single-shot only is a bench-rest setup?

 

[divingin]

Cone is used as a single shot due to the difficulty in getting it to strip a round from the magazine (the taper of the shape doesn't give you a ledge to push the case base.) At least in theory. Bergara uses a cone bolt in their mag fed repeaters. Go figure.

 

[Walt Krafft]

Tubb 2000 rifles have coned bolts and feed just fine.

 

[6ShotsOr5?]

Thanks for asking this question @lazyMlazyK . Where did the bolt picture(s) come from?

 

[lazyMlazyK]

Thanks for asking this question @lazyMlazyK . Where did the bolt picture(s) come from?

Defiance's website. They're one of the action machinists I've been eyeing up.

 

[6ShotsOr5?]

Well since they sell all of these, maybe somebody from Defiance will weigh in.

 

[Just Say Moe]

Great question as I have always wondered also. I am assuming they all require different machining on the barrel chamber end also.
#1 Cone - Bergara mentioned above -
#2 - Savage type?
#3 - Remington type
#4 - Mauser/Springfield/Win 70/Ruger type

 

[Toptom]

I use a deviant on a bench gun it’s a single shot and came with the recessed nose which is the Remington style and works great

 

[Kracken McGraw]

Well since they sell all of these, maybe somebody from Defiance will weigh in.

Defiance has great customer service, phone them.

 

[LVLAaron]

Get the standard flat bolt if you're building a PRS/repeater action.

 

[miningshawn]

Get the standard flat bolt if you're building a PRS/repeater action.

^^^^ I agree. If feeding from the magazine the flat bolt is the way to go.

BTW - If you can wait a week and pony up a few extra dollars, Defiance can and will do custom serial numbers (or letters). And they have a military discount, unlike some of the other action makers.

 

[BigPrince]

All 4 of my Defiance actions including a custom from GAP and the PPR from GAP are recessed. All work great. If you want to go with a prefit barrel, some specify recessed nose. I know Proof specifically does for their prefits.

 

[SGK]

The idea behind the 'controlled round feed' is that the bolt has a 'grip' on the case from the get go. It can be retracted without having to fully close the bolt and then open it again.

The Deviant Elite is different again. (You didn't include it in your snip from their website.) It is cone-nosed, controlled round feed.

Give Defiant a call.

 

[JSH]

The Badrock rifles have a coned bolt.
Don’t be afraid to call them, top notch folks from my experience.

 

[Kurz]

The “South Fork” is a new offering from BadRock Rifles. BadRock is a division of Defiance Machine, who is no stranger to the precision rifle world. The $1995 South Fork rifle is designed from the action up to compete in the “Production” division of the Precision Rifle Series matches.

The South Fork rifle starts with custom receiver that loosely follows the M700 pattern. The receiver will fit a M700 inlet stock or chassis and accepts M700 pattern triggers. The bolt is a two-lug design, but the similarities end there. The South Fork uses a controlled round feed design that work with Accuracy International AW ten round magazines.

The South Fork rifle features controlled round feeding.
Controlled round feed rifles are designed so that the bolt face solidly grips the case head as soon as the cartridge feeds from the magazine. This is incredibly useful if you are shooting the rifle while laying on your side or if you encounter a cartridge that will not chamber and you need to eject it. This is in contrast to a “push feed” type action where the extractor only grips the cartridge after the shoulder of the chamber has pushed it back into the bolt face. Controlled round feed is a highly beneficial feature, but is usually reserved for the more expensive custom actions.

http://8541tactical.com/2019/03/26/badrock-rifles-south-fork-production-class-competition-rifle/

 

[divingin]

Controlled round feed is a highly beneficial feature, but is usually reserved for the more expensive custom actions.

If you consider any Mauser-type action (think old military rifles) a "more expensive custom action", then yes.

I would say it "can be" highly beneficial, depending on your circumstances. Many hunters like it, as aborted chambering attempts are more likely to clear the action, and (reportedly) chambering the round can be quieter than an action where the extractor clicks over the case rim.

If you shoot mostly at a range, clearing a round is not all that big a deal, and in that scenario the added expense and complexity may be more of a drawback than an advantage.

 

[Kurz]

You might try using the link which I supplied at the bottom of the excerpt. This is from an article written by 8541 Tactical, not by me. I used this excerpt for the information regarding the relationship between BadRock and Defiance and the photograph which was embedded in that article.

If you choose to nitpick their definition of CRF you should direct it to them.