Pressure Question

[hydeslinger]

I am loading for my 218 Bee, in a Ruger #1. I am using 40 grain SBK and Lil Gun powder with Rem 6 1/2 Primer new WW Brass.
Here is the question:
I am pushing the load using up to 15 grains of Lil Gun. My groups seemed to get tighter and tighter as I got higher in the pressure range. At 15 grains I stopped with a group just over .375. But, do I have too much pressure?
The primer is not flat, is not cratered, the brass does not stick.
But, noticeably more recoil, and in the web area of the case it has a brighter colored ring, which might indicate a case separation later.
Is this brass safe to reload? Do I have over pressure??
The frustration that I am having is the groups are AWESOME, the velocity is AWESOME at 3550fps, but am I pushing this to far? Hodgdon's site lists a Max of 14 grains with Lil Gun, I know I am over, but again am I pushing it too much?
Will I have a failure at this power/pressure range?

 

[Flintknapper]

Many factors affect chamber pressure besides the powder charge.

I can run the numbers through QuickLoad if you can provide me with the following information:

1. Bullet length (the component part, I'm guessing between .500 & .600)? I need a good number, measure two or three.

2. Trimmed case length.

3. OAL length of cartridge (loaded cartridge).

4. Crimp or no crimp (if crimped, heavy or not).

If you know your barrel length and twist that will be helpful too.

 

[hydeslinger]

I will get that info.. I have everything except the actual bullet length. Let me see is Sierra post that somewhere. Its a Sierra BK. Thanks in advance.

 

[Flintknapper]

I looked on the sierra site and didn't see it. Without...that...I can only guess.

At the very least....I need bullet length, COAL (loaded cartridge length) and your powder charge (15 grs. I believe you said).

 

[gamestalker]

From what I'm seeing on Hogdon's site for a 40 gr. bullet indicates you are over max by a substantial amount. But this isn't taking into account other factors that could allow the charge to go above max, and still remain within safe operating pressures. I load with a number of slow burning powders that can be worked up to well over max. with no problems, but I have no experience with Lil Gun in this respect.

Using a sharpened paper clip, check the inside web area for any internal signs of case separation.

Sounds like you have found a deffinite sweet spot for that rifle!
GS

 

[hydeslinger]

15 grains Hodg Lil Gun at 1.820 Very light Crimp with Lee Crimp die.
Sierra 40 grains Blitz King.
It is based on a load from the nest but I did not get great accuracy at 14 so I worked up slowly to 15 grains, my accuracy really starts at 14.5 so I could back down to that and be happy with under .5 groups. I read on a post on another site guys were running 16-18 grains on Lil Gun in #1's only.. Of course I take that with a grain of salt.
It is really strange, that I am not seeing any pressure with this load other than what I posted.
I loaded some Sierra 45 grain round nose Hornet at a less charge/same powder and saw immediate signs of deep indent in the primer, so I only shot 2 and pulled the rest. Accuracy was horrible in the lower pressure rounds.
I don't know; it's hard to wrap my head around this. I don't want to get hurt or damage my gun, but... Man does it shoot nice at the listed powder charge and bullet.

 

[hydeslinger]

"game" you are right about being over.. But, on the Hodgdon side they list 14g as the max using that bullet/powder combo.. I don't know the percentage but I know that a full grain from 14 to 15 is a fair amount, but... ??

 

[Flintknapper]

Maximum SAAMI chamber pressure is listed at about 46,400 psi.

Guessing at your bullet length (.582) and using your OAL of 1.820" (relatively long) QuickLoad predicts (15.0 grs. Lil'Gun) will give you 50,552 psi, so yes...you would be over.

BUT, without knowing the actual bullet length...that figure could be less or MORE.

 

[hydeslinger]

Thanks for the info.. Kind of troubling ??
But am I going to cause a problem shooting a Ruger #1 at that pressure? does 4k in overpressure = a big issue, I am not really familiar?

 

[Flintknapper]

^^^^^^^^^^^^^ The Ruger # 1 action and barrel are both very strong, however...we don't know that you are at the 4,000 psi figure OVER max.

It could be higher....IF the bullet is longer than what I guessed at, but more importantly...the Burn Rate Factor (in this case .8550) varies (lot to lot) and can easily be 3-5% over or under and in some cases as much as 10%.

With your present load...an increase in burn rate of 5% would shoot you up to approximately 60,000 psi and at 10% it would be 70,000 psi.

I also don't get the same velocity prediction (3,500 fps) from 15.0 grs that you are getting. I'm not seeing that until 16.5 grs. (way over).

You have PM with a print out.

WARNING: Anyone reading this....DO NOT use this information to load from. Always follow (known to be safe) published data from reliable sources.

 

[hydeslinger]

Another interesting thought is this.. I used the Chronograph for the first time the day I clocked the 3550 from the Bee. I was also shooting 222 Remington, the book said 3000(ish)fps with the chosen load in the 222. I was clocking 3250. Could be that the Chronograph is giving false #s.
But, I looked at the PM and will back it down..
The Bee is 1 of 2 #1's (favorites) that I currently own. I don't want to cause harm to it or ME!!
I will back it down below the listed PM and see what I come up with accuracy.
Thanks again!!

 

[Flintknapper]

Be sure and keep close tabs on your brass as well.

If you see a thin shiny ring just above the base of the cartridge, it might very well indicate an impending case head separation.

Don't you just hate it when your best shooting load is just a tad "too hot".




Edit: The Bee head spaces on rim, forgot.

 

[hydeslinger]

I did look at a just fired brass and the case stretch was negligible to not existent. Maybe 1/2 thousand but my mic does not go that low accurately. The shinny ring is another issue. That is what started the post.. Oh well back to the drawing board.
I still have a few weeks before my annual E. Washington Squirrel trip.

 

[NCsmitty]

When the 218 Bee was introduced, it was chambered in many brands and actions, some strong and some not so strong.
You have a very strong action that does not have to adhere to the pressure limits imposed by it's standard SAAMI spec for use in the weaker actions.
An illustration is my M98 chambered in 6.5x55, which was originally chambered in weaker bolt actions and SAAMI spec running near 51K PSI. I am confident that I can run my M98 up to 60K PSI with a good margin of safety.
Your #1 can easily exceed 218 Bee SAAMI spec by 10K-15K PSI, if the brass holds up. You should get a idea of the baseline pressure of your current load to see if it's a keeper. You also need to check the inside of the case for notches indicating case stretch at the shiny line. The shiny line could also just be from die friction.


NCsmitty