|
|
|
It is currently Fri Mar 29, 2024 3:05 am
|
|
Page 1 of 1
|
[ 8 posts ] |
|
Polymer coated bullets, and leading
Author |
Message |
NWReloadN89
Location: Everett Joined: Thu Aug 13, 2020 Posts: 44
Real Name: Nathan
|
So, I happened to pick up some 217gr 30 cal projectiles from SW in Bellingham. 500 in a box for a good price(about 70 bucks). Figured I load them up for 300 BO subsonic affordable plinking load.
Bought them, got them home and didn't think about bullet diameter when I first bought them. It also wasn't on the package. Measured them out to a diameter of .310. Thought to myself, shit! So I went ahead and bought a bullet sizing die, as I'm slowly building up the tools for casting in the future. Figured might as well get it now. Put them all through the sizing die and none of the polymer came off the bearing surface. They all came out to .308 some .307.
Went to test fit one into a case. Took about .002 off the bullet, polymer and lead on the outside of the case. Neck tension on factory die is .305. Tested .306, same out come. tested .3075 no coating came off, seated just fine.
My question is, should I crimp these bullets with a crimp die? I'm going to be firing them in a semi auto. So, I'm skeptical that they may cause leading in the barrel, and/or the bullet to seat deeper if not crimped while cycling in a AR.
I clean after every 300 to 500 rounds with copper plated bullets. But, if these could cause leading, I may end up cleaning after every 100 round lots are fired.
|
Mon Sep 27, 2021 12:12 am |
|
|
MadPick
Site Admin
Location: Renton, WA Joined: Sun Mar 13, 2011 Posts: 51919
Real Name: Steve
|
Whether or not to crimp would depend on how tight the bullets feel to you (neck tension). If you push a round against the table (bullet down), does the OAL decrease? They may be okay without crimp; I don’t crimp most of my AR ammo.
When I load coated 300BLK bullets, I use a Lee universal flaring die to bell the case slightly, which allows the bullet to enter without damage. Then I use a Lee factory crimp die to push it all back together and crimp it a bit.
_________________SteveBenefactor Life Member, National Rifle AssociationLife Member, Second Amendment FoundationPatriot & Life Member, Gun Owners of AmericaLife Member, Citizens Committee for the Right to Keep and Bear ArmsLegal Action Supporter, Firearms Policy CoalitionMember, NAGR/NFGRPlease support the organizations that support all of us.Leave it cleaner than you found it.
|
Mon Sep 27, 2021 6:27 am |
|
|
Caveman Jim
Site Supporter
Location: In my Cave near the Cloquallum Joined: Thu Sep 26, 2013 Posts: 7758
Real Name: Jim Sr.
|
Good info, I haven’t bought polymer bullets nor loaded for subs…. YET.
_________________"You are either with us...as Americans. Or, You are against us. There is no IN BETWEEN." ??? "We cannot negotiate with those who say, 'What's mine is mine, and what's yours is negotiable.'" JFK "Those who would give up essential Liberty, to purchase a little temporary Safety, deserve neither Liberty nor Safety” -Ben Franklin MadPick wrote: I don't think you beat your children enough.
|
Mon Sep 27, 2021 7:16 am |
|
|
beckdw
Site Supporter
Location: Tri -Cities Joined: Thu May 23, 2013 Posts: 2798
Real Name: David
|
MadPick wrote: Whether or not to crimp would depend on how tight the bullets feel to you (neck tension). If you push a round against the table (bullet down), does the OAL decrease? They may be okay without crimp; I don’t crimp most of my AR ammo.
When I load coated 300BLK bullets, I use a Lee universal flaring die to bell the case slightly, which allows the bullet to enter without damage. Then I use a Lee factory crimp die to push it all back together and crimp it a bit. I use the same method and have not observed any leading.
|
Mon Sep 27, 2021 11:03 am |
|
|
NWReloadN89
Location: Everett Joined: Thu Aug 13, 2020 Posts: 44
Real Name: Nathan
|
Madpick, I will have to test this when I get the chance. However, there maybe a variable to the OAL with most of the bullets having lead nose and not much polymer coating on the tips. Much like a SP from Hornady or Sierra.
However, I do have ogive measurement tools. Which could help with that measurement. More tests are in order before a mass load session, that's for sure.
|
Mon Sep 27, 2021 2:58 pm |
|
|
MadPick
Site Admin
Location: Renton, WA Joined: Sun Mar 13, 2011 Posts: 51919
Real Name: Steve
|
It doesn't matter if there is OAL variation; we are just talking about a single cartridge here. Measure its OAL, then push it down on the table, then measure it again. Did it get shorter, i.e. did the bullet push into the case at all? That's what you're checking for.
_________________SteveBenefactor Life Member, National Rifle AssociationLife Member, Second Amendment FoundationPatriot & Life Member, Gun Owners of AmericaLife Member, Citizens Committee for the Right to Keep and Bear ArmsLegal Action Supporter, Firearms Policy CoalitionMember, NAGR/NFGRPlease support the organizations that support all of us.Leave it cleaner than you found it.
|
Mon Sep 27, 2021 3:32 pm |
|
|
hartcreek
Location: Union Gap Joined: Sun Mar 27, 2016 Posts: 1722
Real Name: Randall Knapp
|
I crimp everything I load so that I do not have to worry about neck tension. I have been using powder coated bullets for quire a while and getting no leading. You got by lucky this time reloading you need to get the universal flaring die as it will save you a lot of grief. Your oal for a magazine fed firearm is what fits the mag and feeds.
|
Mon Sep 27, 2021 10:08 pm |
|
|
Yondering
Site Supporter
Location: Skagit County, in the woods Joined: Tue Apr 7, 2015 Posts: 1058
|
NWReloadN89 wrote: So, I happened to pick up some 217gr 30 cal projectiles from SW in Bellingham. 500 in a box for a good price(about 70 bucks). Figured I load them up for 300 BO subsonic affordable plinking load.
Bought them, got them home and didn't think about bullet diameter when I first bought them. It also wasn't on the package. Measured them out to a diameter of .310. Thought to myself, shit! So I went ahead and bought a bullet sizing die, as I'm slowly building up the tools for casting in the future. Figured might as well get it now. Put them all through the sizing die and none of the polymer came off the bearing surface. They all came out to .308 some .307.
Went to test fit one into a case. Took about .002 off the bullet, polymer and lead on the outside of the case. Neck tension on factory die is .305. Tested .306, same out come. tested .3075 no coating came off, seated just fine.
My question is, should I crimp these bullets with a crimp die? I'm going to be firing them in a semi auto. So, I'm skeptical that they may cause leading in the barrel, and/or the bullet to seat deeper if not crimped while cycling in a AR.
I clean after every 300 to 500 rounds with copper plated bullets. But, if these could cause leading, I may end up cleaning after every 100 round lots are fired. Should've done your research before sizing all the bullets too small. At this point you'll probably get some leading no matter what; .307-.308 is too small for a good bore seal in a low pressure subsonic load. At .310" you would've been fine. Absolutely do not crimp. Coated bullets should never be crimped if you can avoid it; a crimp cuts into the coating but also is likely to scrape some coating off as the bullet leaves the case. Crimp is generally unnecessary in this application anyway unless your bullets are way too soft, or you don't have enough neck tension. Personally I want the die to set sized neck diameter at .307", and a sized bullet diameter of .309"-.311". You have to play with diameter a bit sometimes to figure out what works best with your rifle, but the general rule is you need bullet diameter to be at least .001" larger than the bore. Done right, you can shoot coated bullets indefinitely without cleaning the bore, but in this case with the small bullets, you'll have to keep an eye on leading. If it happens, wrap some strands from a copper chore boy pad around an undersized bore brush so that it's a tight fit from the chamber end; a few strokes back and forth will take care of it. Don't shoot these undersized bullets through a suppressor.
|
Mon Sep 27, 2021 11:48 pm |
|
|
|
|
Page 1 of 1
|
[ 8 posts ] |
|
Who is online |
Users browsing this forum: No registered users and 30 guests |
|
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot post attachments in this forum
|
|