Thinking about cannelure on 230g FMJs and 250FTX

Talk about your 450b reloading experience, ask questions, etc...

Moderator: MudBug

Forum rules
Please try and keep it safe!

This information is the responsibility of the community, not the forum. 450bushmaster.net is not responsible if you blow yourselves up.

Thinking about cannelure on 230g FMJs and 250FTX

Postby Bowshot58 » Tue Apr 12, 2016 6:15 pm

Hi, I have a 450BM with an 18" tromix barrel/bolt and just completed Hoot's CCWS on a new M16 style bolt carrier! Also modded the ejection port with posts from here!
20160412_ar15_450bm_2.jpg
20160412_ar15_450bm_2.jpg (39.72 KiB) Viewed 14909 times

I figure the weight should stay put as the M16 style bolt carrier has even more surface area than the AR15 BC to adhere to. Hoot is this mod still holdig up on your rifle??

Question: Maybe this has been done in the past? Has anyone ever tried using a cannelure on the 230g fmj or 250g FTX, with either a Taper crimp at the top of the case or a stab crimp down lower?
I am seeing bullet pull after just one bolt cycle...even with Hornady 250FTX factory ammo, so I am trying to eliminate it on my reloads.
But the gun is MOA with Hornady factory ammo, so is there some reasonable explanation on how this works? I would think that .001-.002 bullet pull would add enough variation to cause problems?
Also a Big THANKS! to Hoot and the Crew for their informative posts here for the 450BM
I would not have gotten this far without em!!!!
:D
Thanks!
bowshot58 in Michigan
Bowshot58
 
Posts: 7
Joined: Thu Oct 29, 2015 4:41 pm
Location: SouthEast Michigan

Re: Thinking about cannelure on 230g FMJs and 250FTX

Postby Hoot » Tue Apr 12, 2016 9:32 pm

Yes,it is still doing fine, though I haven't shot it since getting the Bartz Upper. Once you go Bartz, its hard to go back. :lol:
Actually, I like mostly everything about my original 450b upper besides the fact that I sold my original factory 20" barrel and got a Franklin 20" barrel with a rifle length gas port. Great barrel, but I don't care for the rifle length gas port once I got it. The mid-length is a better fit, but I'd even go back to a carbine over the rifle. Just my opinion.

The roller style cannelure tool, while a means to an end has IMHO, a glaring shortcoming. It tends to push the displaced copper in a little, but also up on either side of the trench. That makes it higher than the rest of the bearing surface, at least until it obturates as it enters the bore. Then it doesn't matter. Why do I think it still matters you ask? Its hard enough getting good neck tension with the bullet's bearing surface in full contact with the case, but when it's riding up on those ridges, there is less tension. Even if you taper crimp down into that cannelure at the mouth, the ridge that is still buried down in the case is a factor.

This is important. if you have a resizing die, you may be able to size the ridge back down, but where's it going to go? Back into the cannelure trench? That in theory (see sig), will yield less consistent tension from one load to the next. The important part is that I'm speaking from gut feeling, not experience. If someone wants to, and perhaps they've already done so, try it and report back, I'm all eyes.

Hoot
In Theory, there is no difference between theory and practice. In Practice, there is.
User avatar
Hoot
 
Posts: 5083
Joined: Tue Feb 09, 2010 9:34 am
Location: Minnesota

Re: Thinking about cannelure on 230g FMJs and 250FTX

Postby commander faschisto » Tue Apr 12, 2016 9:51 pm

My Hootster CCWS has been in my factory BC for several years...if the surfaces were clean, it is NOT going anywhere once the epoxy cures out. The JB shear strength X square inches of surface = don't worry about it. Ever.

You should search out Texas Sheepdog's load development information for the 230gr FMJ flat-toppers...he's gotten them to do some amazing things, no cannelure required. And, contrary to what many believe, these big flat point FMJs will not only punch through "whatever" with gusto, but they do indeed also expand quite nicely as well. TSD has much to tell you about these loads.

EDIT: I forgot to mention, be sure to post pics of the finished Thumper...looks great so far!
Isa Akhbar!
NRA Life Member
Oklahoma Rifle Association member

Heavily armed; easily pissed.
User avatar
commander faschisto
 
Posts: 1484
Joined: Tue May 31, 2011 6:32 pm
Location: Oklahoma City USA

Re: Thinking about cannelure on 230g FMJs and 250FTX

Postby Hoot » Wed Apr 13, 2016 6:48 am

commander faschisto wrote:...snip...
You should search out Texas Sheepdog's load development information for the 230gr FMJ flat-toppers...he's gotten them to do some amazing things, no cannelure required. And, contrary to what many believe, these big flat point FMJs will not only punch through "whatever" with gusto, but they do indeed also expand quite nicely as well. TSD has much to tell you about these loads.


Actually, I have a 450b range day scheduled today. The main subject is the 230fmj RN. Don't have any FN ones. In my last ho-hum outing with them, I was left with the impression that the groups might be tightening up jut as I hit the highest load I had taken with me. There was room for mo powah as far as the Bartz was handling them and the brass was not complaining either. So I'll be giving them another at bat with more velocity today. Not expecting miracles given the 3 or 4 tries previously using them, more like a last hurrah.

Hoot
In Theory, there is no difference between theory and practice. In Practice, there is.
User avatar
Hoot
 
Posts: 5083
Joined: Tue Feb 09, 2010 9:34 am
Location: Minnesota

Re: Thinking about cannelure on 230g FMJs and 250FTX

Postby commander faschisto » Wed Apr 13, 2016 9:47 am

Veddy good...that will give us a good comparison with the flat-tops that TSD has worked up. Just thinking about them, the two designs have got to have significantly different aerodynamics at the speeds generated in the 450b loadings. Do tell about the RNs when you finish with them!
Isa Akhbar!
NRA Life Member
Oklahoma Rifle Association member

Heavily armed; easily pissed.
User avatar
commander faschisto
 
Posts: 1484
Joined: Tue May 31, 2011 6:32 pm
Location: Oklahoma City USA

Re: Thinking about cannelure on 230g FMJs and 250FTX

Postby Bowshot58 » Wed Apr 13, 2016 10:00 pm

Thanks for all the info on Hoot's CCWS, I plan to test it out in the next week or so. I will get some picks of my 450BM up.

I can't seem to locate a source for the 230g FMJ FN - flat-toppers...has anyone seen or purchased any recently?

Hoot - I am intrigued by the idea of creating a cannelure tool to use a roller (below) which might mitigate the ridges on either side of the cannelure...not exactly perfect (theoretically) but should optimize the non-cannelure surface area? Concept drawing -not to scale.

image.jpeg
image.jpeg (22.91 KiB) Viewed 14848 times


I was able to get some good 230g RNs from (Rocky Mountain Reloaders) RMR for $80/500 or 16 cents each...shipping free!
I would really like to use these for all around load target, steel, maybe even deer... :o

Thanks,
Bowshot58
Bowshot58
 
Posts: 7
Joined: Thu Oct 29, 2015 4:41 pm
Location: SouthEast Michigan

Re: Thinking about cannelure on 230g FMJs and 250FTX

Postby commander faschisto » Wed Apr 13, 2016 11:03 pm

Nosler Sporting Handgun bullet line includes a 230gr FMJFP, cat. no. 44964:

http://www.nosler.com/sporting-handgun-pistol-bullet/

This is the lowest price I found: http://www.ammoatcost.com/catalog/produ ... id=1483199
Isa Akhbar!
NRA Life Member
Oklahoma Rifle Association member

Heavily armed; easily pissed.
User avatar
commander faschisto
 
Posts: 1484
Joined: Tue May 31, 2011 6:32 pm
Location: Oklahoma City USA

Re: Thinking about cannelure on 230g FMJs and 250FTX

Postby Hoot » Thu Apr 14, 2016 5:53 am

I got most of the range report from yesterday done, but most of the results were dismal in terms of accuracy. I've seen patch and ball muzzle loaders that grouped better at 100 yds! :| They were for the most part, out of control. I'm absolutely finished with blowing my vacation time on multiple range days that produce dismal results with the 230gr FMJ RN and using a stab crimp. Finito!

The flat nose may perform better, but I'm loathe to waste time finding out they don't. There are so many excellent choices for a nickel more per round, in boxes of 100. My time and mental health are worth more than that. :roll:

Look for the range report this evening.

Hoot
In Theory, there is no difference between theory and practice. In Practice, there is.
User avatar
Hoot
 
Posts: 5083
Joined: Tue Feb 09, 2010 9:34 am
Location: Minnesota

Re: Thinking about cannelure on 230g FMJs and 250FTX

Postby commander faschisto » Thu Apr 14, 2016 11:58 am

Hootster...we do appreciate that you soldiered bravely onward 'till the bitter end! I think this is like a science experiment that failed to prove the proposed hypothesis...at least you got to the answer. Negative results are just as valuable as positive results, just a whole lot less fun... :|
Isa Akhbar!
NRA Life Member
Oklahoma Rifle Association member

Heavily armed; easily pissed.
User avatar
commander faschisto
 
Posts: 1484
Joined: Tue May 31, 2011 6:32 pm
Location: Oklahoma City USA

Re: Thinking about cannelure on 230g FMJs and 250FTX

Postby plant_one » Thu Apr 14, 2016 12:16 pm

commander faschisto wrote:Nosler Sporting Handgun bullet line includes a 230gr FMJFP, cat. no. 44964:

http://www.nosler.com/sporting-handgun-pistol-bullet/

This is the lowest price I found: http://www.ammoatcost.com/catalog/produ ... id=1483199



dont forget to watch for blems at SPS. their current list price for them is $0.15 per bullet but they're OOS at the moment

http://www.shootersproshop.com/nosler-p ... 100ct.html
User avatar
plant_one
 
Posts: 1109
Joined: Sat Mar 19, 2016 8:58 pm
Location: Oakland County, MI

Next

Return to Reloading for the 450b

Who is online

Users browsing this forum: No registered users and 22 guests