New SR1911 and Short OAL - How Short is Too Short? - Nevermind, I'm Losing it!

[tdogg]

All,

Edit:  Nevermind, I'm an idiot.  Apparently I can't read my analog calipers.  Getting old is hard!

This isn't my first rodeo but I'm questioning what I should do moving forward.

I recently won a Ruger SR1911 in 45 ACP.  I plan on shooting it in USPSA single stack major.  I have a pile of 200 SWC bullets that I've loaded for my CZ97BD for years (not so much lately as I've moved away from shooting the 97BD in comps).  I was loading those to an OAL of ~1.250, which gave just a bit of the shoulder protruding over the case mouth (which I found was needed for reliable feeding).  I did a plunk test with this ammunition in the SR1911 and it wouldn't plunk.  I had to seat them deeper by 0.010 inch to pass the plunk test which means I need to add another 0.010 inch to cover process variability, so an OAL of 1.230 should reliably chamber in the SR1911.  I don't know if that will work in my 97BD or the 1911 yet but I will test it.  The point of all this is that apparently my SR1911 chamber is shorter than the 97BD.

I also won a batch of 500 bullets from Summit City and I chose to get their Hitek coated 230 gr RN sized to 0.452.  I wasn't thinking at the time that I would have any issue loading them to a reasonable length but alas Murphy's is always with us.  When I was determining the maximum OAL I can run with this new bullet in the SR1911, I found it to be really short 1.105 1.205 inch.  I thought, there must be something wrong with this particular bullet so I did it again with a different case and bullet and found the same result.  Apparently this bullet profile is a short fat RN and that is causing the short OAL.

I haven't loaded any yet.  I will have to reduce the starting load some amount to stay safe.  I haven't done the math to estimate the percent volume reduction with this short OAL vs the published load data OAL of ~1.250 inch.  Before I spend any more time on this, I thought it best to ask the question and see if anyone else had experience loading short for 45 ACP.

So is ~1.100 1.200 inch too short for 45ACP?  If I'm just going to run into feeding issues, then I may just cut my losses and sell/give these bullets to my cowboy action buddies.  They won't have issues loading these for their revolvers.

Thoughts?

Cheers,
Toby

[Wobbly]

Photos of the bullet with and without the case would really help this thread.

1.105" doesn't sound too short, but make up a small batch and try them.

Not every bullet can be used for reloading in every gun. You might end up better by swapping them for the same count SWC.

[tdogg]

I took my dummy inert OAL cartridges and have been cycling them through with a magazine.  The SWC variants (both short and long) are hanging up.  They feed about halfway into the chamber then bind up.  Thus far the RN bullet at the short OAL seems to feed fine.

Here is the lineup, the bullet on the left with my two short max OAL RN, then the shortened SWC, and finally the original SWC on the right that I run in the 97BD:


Here is how deep the RN is getting seated into the case:


I'm not sure what is causing the circumferential scratches in the cases.  These were cycled through the gun a number of times by hand so they are a little beat up.  I will have to keep and eye on that, might need to deburr the feedramp on the barrel?

I'm going to load up a small ladder and see how they run and check for PF.

Cheers,
Toby

[tdogg]

Alright, I must be losing it.  I loaded up a ladder of charges today and while setting the OAL I realized that the OAL was 1.200 not 1.100 inch!  While it is still short, it is reasonable and well within the range of normal.  I will shoot them and post up my findings.

Cheers,
Toby

[tdogg]

Made it out today and shot the load development.  The ran with a few hiccups.  I'm still breaking it in as it only has about 40 rds through it.  This is my first foray into the 1911 realm.  I will figure out how to get it running 100%.

Equipment
Caliber:  45 ACP
Bullets:  Summit City 230 RN Hi-Tek Coated
Brass:  Mixed
Powder:  Maxam CSB-5 (yes I still have a pound of this)
Max Velocity:  Unknown, max charge listed was 4.2 gr
Primer:  WLP
OAL:  1.190 inch
Pistol:  Ruger SR1911
Qty:  3 rounds each
Distance:  10yds
Weather:  50F and clear
Chrono:  Lab Radar

Load         Avg Vel           SD
3.4gr           705             12.4
3.6gr           730             10.7
3.8gr           756             4.1
4.0gr           787             18.4
4.2gr           812             11.5  Max Load!

Notes
These all fed while shooting but I did have a couple of failures when initially loading.  I found that if I used the slide release it would jam but if I sling shot the slide it would feed every time.  I'm going to chalk this up as break in issues.  I think the gun needs to be shot a bit to break it in.
The 3.6 gr charge was one ragged hole (0.3 inch center to center).  All the groups were an inch or less.
My USPSA load will be 3.7gr just to give a little cushion to make PF.