Lifter guns
 

About what time did the lifter guns change from the 90 degree breech face to water table to the rounded inner corner that went on into the later guns ?

I've been told the older guns with the 90 degree sharp corner had a tendency to crack there dunno if that's true or not . But was curiouse when they went from the sharp 90 degree to the shall we say rounded inner corner .

I am sure theres a more technical way to say that but I don't know it .

generally referred to as a radius i think

I'd need to get the book out, but if I remember correctly-

a 14K numbered lifter i had was not a radius frame - but it seem that it was near the end of the sharp corner design

http://parkerguns.org/forums/picture...&pictureid=590

This one is square in the corner .

http://parkerguns.org/forums/picture...&pictureid=543

This ones rounded in the corner .

Was what I was told correct and these square corner guns have a tendency to crack ?
Or was it more likely any that did were shall we say overly abused ?

how many are seen with cracks? I know that has been mentioned in other threads on the topic- and the Ithaca Flues supposedly also had an issue with a 90 degree design. the word there was it was from heavy loads- the Ithaca frame had a subtle change about 1920 to remedy that, so much later than the Parker change.

So, With the common black powder loads of the day, I wonder if too heavy a load could have been the reason for the Parker design. Could very early smokeless loads caused an issue?

heck- could it just be the radius was easier to do the final fitting of the barrel with?

wiser Parkerites than I would need to answer the question

Well it's a pretty good idea I would think if a fella just wanted a lifter gun to shoot some to go ahead and find one in decent shape that was "radius" cut rather then square cut ?

Craig I don't know if that's the best thing to do. My Lifter 8526 has the square corner and is not cracked. Shooting it with Black Powder loads it may crack or it may not. It was not real expensive. For a shooter may be better to take the risk saving up front.

Way I see it if you avoid one that's cracked conditon and price are major factors not what could happen. I have another Parker hammer gun that was several times the lifters price, it's a radius corner.

William

I have seen several early lifters which have cracked at the corner between the water table and the standing breach. I believe the change to the radius corner was about the low 14K range.
A tight included angle is a stress riser. The reason is that stresses which develop from a shot need to be distributed so there isn't a concentration at a single point. A radius has an arc which distributes the stresses like a sunburst (or in this case a quarter sunburst) a non-radiused corner only has two directions, 90 degrees to each other, where stress can be distributed. Consequently the stresses are much higher in each of the two directions than if they were distributed around this quarter-arc.
Only just a while back there was a $250 grade lifter that sold at auction, in PA. It was cracked at this intersection. I believe our beloved Stosh (Dave Suponski) also has a cracked lifter.
The second example you linked is likely a grade 2, but if you look at the photos of grade 3 and up lifters on the home page, under grades, you will also see there is a reinforcing bead on the side of the frame, just above the lock plates, at this intersection.

No cracked lifters here Edgar. I don't know who bought that gun.

My most recent Parker purchase 14290 is a 16 Ga. O frame with square corner Breach ,No Cracks ! Hunted Pheasants with it this season and Woodcock !