Jumping solids, and 'bore rider' throat?

[memilanuk]

I've been doing some reading/listening lately with the intent of stretching my 'LR' rigs out a little further (1500+). I've never played with solids in any way, shape or form, so I'm starting from the point of they're probably not 'necessary' for what I want to do, but I'm curious about them nonetheless.

Listening to some recent podcasts that touched on a) extended bullet 'jump' (Modern Day Sniper #14 w/ Scott Satterlee) and b) solid projectiles (Everyday Sniper #236 w/ Josh Kunz), I started to wonder if jumping solids relatively 'large' amounts in bigger 'magnum plus' cartridges worked as well as it appears to with jacketed bullets in smaller cartridges?

I've seen a few questions in the forums about using solids from a mag fed .338LM (one of the gun/cartridges I have available), with the answer usually being that the OAL seated out for a 'normal' jump would be too long to work from the magazine. But if solids responded well to large jump... ya see where I'm going with this?

Kinda curious if this has been tested in any kind of detail?

The other part of my question is about the 'bore rider' throats I see mentioned with various chamberings - but I haven't seen a lot of specifics as to what precisely a 'bore rider' throat entails? Elsewhere I found some info that indicated that it involved something between the normal 'tight' freebore I'm used to seeing in match guns (0.0005" or so over nominal bullet diameter) and actual full height lands - sometimes half height? Is the intent for the bullet to actually engrave partially into this area upon chambering, or during initial firing? Also, I saw some posts that indicated that bore rider throats appeared to wear approximately 2x as fast as regular 1'30 throats? Yes / no / depends?

Thanks!

 

[timintx]

The leade angle is standard 1.3 degrees but in a way it is not quite as important as it relates to throat erosion. Bore riders such as cutting edge bullets require no special freebore length or diameter because the front half of the bullet slides on to the lands . The cutting edge has a seal band in which sets right at the top of the case when loaded ,the seal band will not go into the freebore so now your new throat is the beginning of the freebore and back or basicly the gap between your case mouth and the freebore champher which is usually 45 degrees You would set seating depth just like any other with about .035 of seating depth to play with before the seal would contact the case. When fired the rear of the bullet behind the seal band digs in slightly in to the lands as it is closer to the groove diameter . On my Cheytac one free bore works for all bullets from 350 ,377,400 and 425 grain. Same on my 338 as well. They require load work up no different from jacketed bullets. With most solids now you can get faster velocities than jacketed bullets with a given pressure as well, less rifling marks makes for better a bit better bc too . Hope this helps sir.

Tim in Tx

 

[memilanuk]

Thank you, sir, for that info. A friend of mine had mentioned the Cutting Edge bullets and their seal-tite band, but his explanation was a little light on the details of how/why it worked. Now I know more than I did before

I am still interested in the concept of the 'bore rider' *throat* that I see mentioned from time to time, as well as hearing from anyone who's experimented with jumping solids in a longer throat.

 

[memilanuk]

@bohem
@Alan Warner
@sstacllc

Any experience jumping solids long?

 

[bohem]

I jumped the smaller ones like my 6mm designs a 6.5 designs over 0.1"

We did get a report from a customer years ago that the 198 "was the worst bullet ever" but he was shooting them in a 300NM with 0.360 of freebore (originally, no idea what it was later) for 240 SMKs

His buddy tried them in a 300wsm at 0.050 off the lands and without any load dev at all shot a 3" group at 1000.

Turns out the 198 doesnt handle a jump of 0.315+ of jump

The limit in what I tried seemed be around 50% of the bullet diameter before I saw problems that couldnt be solved with a charge weight change.

 

[sstacllc]

@bohem
@Alan Warner
@sstacllc

Any experience jumping solids long?

Some and only with the smaller stuff. I do have a bore rider type reamer for my 6 creed. 248 freebore and full thickness rifling is at about .750