How much is too much Jam?

[inferno218]

Long story short I had previously ordered ammo from a custom ammo company. My wife finally decided to let me reload my own ammo. Once I got into it I realized that my load was jammed .06". I copied the load I was ordering.

From what I understand this is way too much, but I will say this ammo is very consistent and very accurate. I never thought much of it because I can camber and extract a loaded round with no issue, no hard bolt lift and no primers blown...

Without naming names or too many details should I stay with this length or reduce the amount of jump.

Any help is appreciated and if more details about the load are needed I can give them.

Thanks

 

[InfScout1/69]

If your not having pressure issues and chambers and extracts perfectly fine and shoots to your liking.. I see no issues with it... And you get to save some powder!! Lol

 

[pawprint2]

For me "too much jam" is when you can no longer extract loaded round without leaving the bullet in the tube (powder everywhere), or that the act of extraction changed the OAL. Even if a "deeper" jam tended to give a slightly smaller group, the safety issue would trump it, for me.

 

[parkervbar88]

ok if the PB&J causes the bread to get soggy then you definitely have too much jam

 

[FCS]

Long story short I had previously ordered ammo from a custom ammo company. My wife finally decided to let me reload my own ammo. Once I got into it I realized that my load was jammed .06". I copied the load I was ordering.

From what I understand this is way too much, but I will say this ammo is very consistent and very accurate. I never thought much of it because I can camber and extract a loaded round with no issue, no hard bolt lift and no primers blown...

Without naming names or too many details should I stay with this length or reduce the amount of jump.

Any help is appreciated and if more details about the load are needed I can give them.

Thanks

0.060", 60 thousands jam? More then needed but if it works, run with it. Typically, jammed 0.060" you are not going to be able to close bolt w/o fair bit of force and if you do then you'd better have a lot of neck tension to keep bullet in case.
Did the custom ammo have that much jam or when you duplicated the OAL with your lot # of bullets it was jammed? New lot # of bullets, I have close 0.060" difference in comparator OAL vs old lot# of bullets to touch lands.

What bullet are you running?
What caliber?

 

[inferno218]

0.060", 60 thousands jam? More then needed but if it works, run with it. Typically, jammed 0.060" you are not going to be able to close bolt w/o fair bit of force and if you do then you'd better have a lot of neck tension to keep bullet in case.
Did the custom ammo have that much jam or when you duplicated the OAL with your lot # of bullets it was jammed? New lot # of bullets, I have close 0.060" difference in comparator OAL vs old lot# of bullets to touch lands.

What bullet are you running?
What caliber?

Yes, I have kept some of the original ammo for a point of reference.

It is 223 with 80VLDs

 

[FCS]

Yes, I have kept some of the original ammo for a point of reference.

It is 223 with 80VLDs

Are you loading to same Overall Length or to same Comparator Overall Length?
JLK VLDs or Berger VLDs?

Only reason I can see to jam is if you are unable to get enough of a slower burn rate powder in case to get desired velocity/accuracy as jammed is worth about 0.5 gr of powder.

 

[inferno218]

I guess my main concerns are:

A) is this safe for the long run?
B) would it be smart to reduce to say .020 or .010 instead of .060?
c) Are there any gains from this much jam?

 

[inferno218]

Are you loading to same Overall Length or to same Comparator Overall Length?
JLK VLDs or Berger VLDs?

Only reason I can see to jam is if you are unable to get enough of a slower burn rate powder in case to get desired velocity/accuracy as jammed is worth about 0.5 gr of powder.

They are berger 80vlds. I can hear powder shake freely when I shake a loaded round.

 

[FCS]

I guess my main concerns are:

A) is this safe for the long run?
B) would it be smart to reduce to say .020 or .010 instead of .060?
c) Are there any gains from this much jam?

A - If you are not getting flat primers, pierced primers, ejector swipe or other signs of high pressure then you are plenty safe from a pressure standpoint.
B - Jammed is jammed, no appreciable difference between 0.010" or 0.060" from an internal ballistics standpoint. Disadvantage if you go with less jam (though this is a 223 and won't happen for many, many rounds) is when throat erodes and some bullets are jammed, some are not. Sorting bullets by base to ogive length, into groups of + / - 0.002", will minimize that effect as throat erodes and OAL is static. I'd chase the throat if you do want to continue with jammed bullet. Again, is a 223 so not much chasing will be needed, at least not like a 6.5-284 would need to have throat chased.
C - No real gain, no real loss.

What powder?
How much?
I personally like to jump the Berger VLDs 0.040" or more, depends on what the rifle likes. Lots of others like to jam the Berger VLDs 0.010" or so.
If load is working well, not seeing any pressure signs on brass, bolt lift is easy....I'd run it.

 

[shoot4fun]

How do you know you are jammed that much? What are you using to measure? Normally you want 5 or 10 thousandths jam if any at all because more will cause the bolt to be very difficult to cam over.
When I shot a 6PPC in BR comps I would just barely seat the bullet and let the lands finish the job. But there was very little neck tension so it worked fine.

 

[inferno218]

I am using the Hornady bullet comparator tool.

I am using 22.5 gr of benchmark. going to try 2000-MR next.

its a 8 twist 22" and a surefire socom can.

 

[shoot4fun]

I am using the Hornady bullet comparator tool.

I am using 22.5 gr of benchmark. going to try 2000-MR next.

its a 8 twist 22" and a surefire socom can.

It can lie! Black magic marker on the bullet and then chamber it carefully. If you have a lot of jam then the marks you see will be a lot more rectangular than square.

 

[No1]

I consider an engraved length half the width of the lands to be sufficient and no added benefit with more than that, of course every bullet and rifle is different. 1/2X engraving would be about .025" for most 30 caliber barrels. but if you are by my WAG 1X approximately and it's working then roll with it.

 

[inferno218]

It can lie! Black magic marker on the bullet and then chamber it carefully. If you have a lot of jam then the marks you see will be a lot more rectangular than square.

I tried the sharpie on two rounds this morning. What's funny is when I extracted them they didn't show any sign of markings, but they looked visibly shorter.

I measured the base to ogive and it was .05 less than a non chambered round. So my round when chambered essentially has a jam of .010".

I must has just enough neck tension to extract, but also allow to round to slide back into place when being chambered?

 

[Early Cuyler]

If it shoots and you're not seeing any pressure/safety signs run it. I shoot with a guy that jams his 130 VLDs 0.2" in his 6.5x47. No that's not a typo either. He regularly places in the top 3 of the 1000yd shoots and still has excellent brass. Not sure if he can extract an unfired case though without pulling the bullet.

 

[BDA2]

Of all the things I understand totally...... This is not one of them..... my brain hurts.

Posted Via Glade Plug In.

 

[super_poot]

ok if the PB&J causes the bread to get soggy then you definitely have too much jam

You are definitely doing this wrong. You need to put peanut butter on both pieces of bread first, then you can use as much jam as you want and the bread will not get soggy.

 

[dauntedfuture]

Its called soft seating, its a good place to start with 80 VLDs. Play a little with neck tension if you want but you will be committed once you chamber a round and not be able to extract it.

 

[Xtremegunnr]

Depends how much bread you have.....