Wondering what a stop-ring bullet is & why anyone would use it I've read this thread a couple of times & I'm still not clear.  Call be dense.

Am I to understand that the throat of a rifle made for SR bullets has an area just in front of the case mouth that has a diameter significantly larger than the groove diameter?  If so, is this area similar to but of larger diameter than what we call freebore in modern throats, which is typically groove diameter or, at most, 1 to 2 thousands over groove diameter?

If my understanding is correct, I would expect the large bullet ring to be squeezed down and spread back (finning) when fired & potentially have a negative effect on accuracy.

I've found examples of SR bullets but nothing on the throat dimensions.  Does anyone have a photo or illustration of a SR chamber & throat?

Wayne

At this point, I think it's about time to show a stop ring bullet. This is the bullet I use in my Aydt. As the barrel has a long throat, I set back the stop ring so the front bearing band would engage the rifling. It performs reasonably well especially for a rifle I only shoot once a year.

I have no experience with SR type bullets but in my way of thinking the band is a intererence fit between the front of the case and the beginning of the throat, the SR being at or near  the diameter of the chamber, not the groove. The case is just short enough to squeeze the SR band into the throat while the bullet at the back of the base ring is groove diameter and the front/nose of the bullet at or near bore diameter. That way the gas leakage is at a minimum and hopefully the SR can be reduced at entry of the throat without affecting accuracy. I figure I'm wrong but I can't see how the bullet's SR serves any purpose otherwise. Thanks for the corrections when they come, good read so far.

yamoon wrote on Jan 1^st, 2018 at 2:58pm:


This is approximately how I do it, also.

I use a 32/40 die, w/o the expander and a 30/30 case. That gets rid of the shoulder area, that can be different in every 8.15x46R chamber.

I chamber the formed case and if it doesn't fit, trim it back, by the amount that it sticks out of the chamber. I put 10 gr of Unique in and fill with C of W, cap it off with about 3/16 of old lube (Darr in my case) and fire form it. I then trim it back until the ID is groove diameter ( usually about 1.94 - 1.95 long) for my rifle. The NEI, will also chamber at that length, with thumb pressure.

I also use the NEI SR bullet and can get ~5" 10 shot groups at 200 yards with it. 

The following targets, are all shot in ASSRA (BR) or ISSA (OH) matches, using the NEI SR bullet, accept the 5 shot group, it was shot with a spitzer bullet. The BR targets are BSed  and the OH targets where shot with the SR in the case. The scores are very good for me

For BR, I have several other bullets that I use and shoot BSed and they will do a lot better.

My load is 12 gr 4227, BSed or from the case. I use pistol primers, mostly but, I can't tell much, if any difference using rifle primers. 4227 doesn't seem to care much about primers, in any case that I use it.

Frank

oneatatime wrote on Jan 1^st, 2018 at 12:39am:


JägerWilhelm wrote on Jan 1^st, 2018 at 4:37pm:


So, based on the above comments & assuming the case walls are typically 0.010” thick, the diameter of the stop ring is 0.015" to 0.020” larger than the groove diameter of the bore.  Boy, I'd sure like to see what an undamaged bullet looks like after it's fired through the rifle.  Has anyone tried downloading to the point that the bullet just exists the bore & fired a round into soft material to catch it?

I expect someone has made a chamber/throat cast of their stop ring rifle & has an illustration of the chamber/throat.  If so I'd sure like to see what it looks like.

Wayne