Seat to Cannalure?

[hounddawg]

Question about using Hornady .224 55gr SP with cannalure. trimmed LC cases, TAC powder, CCI SR magnum primers.

To go get the bullet to seat to cannalure I end up with a COL of 2.182. I don't have a Hornady manual but the TAC powder guide recommended a COL of 2.24 for a 55 grain Sierra Blitz Kings. At 2.24 I ended up with so so groups at 100 yards using varying loads from 23.4 to 26.0, 5 shot groups averaged around 1.5 inches. best group was 1.0 inches with a flyer @ 26.0 grains, worst was 3.2 inches @25.8 grains. No pressure signs at 26.0 which was the top end for a 55gr using the Ramshot online guide.

I am shooting a DPMS match upper, 1 - 8 twist. I am thinking about doing another workup this time seating to cannalure. Looking for opinions here and if someone that has a Hornady book would post what Hornady recommends for a COL and loads for TAC I would appreciate it.

Also the age old question on whether to crimp or not crimp. These will be used for HP match practice using reduced targets.

[DiscoRacing]

You can get the load data that Western has here

http://www.powdervalleyinc.com/

You do not have to set back to the channelure...

[hounddawg]

thanks for the quick reply. The Western load data was what I was used for the initial workup but they don't have any data for the Hornady 55gr SP WC. I used the load data they had for the Sierra 55 gr Blitz King figuring it would get me in the ball park at least.

Most of my reloading experience is with lead pistol bullets, still learning this rifle stuff. With pistols I checked COL with the barrel and used a light crimp.

[wncchester]

"Seat to Cannalure?"

You sure can if you want to. Book OALs are starting places, not engraved in stone.

I've been reloading over four decades, I've never even looked at a book OAL nor did anyone else in my generation. In fact, early loading data rarely even listed an OAL. We knew it had to feed and chamber, after that it seems they sorta thought we could figger out what worked for our guns ourselves.

[steve4102]

From Western Powder load guide page 2.

SPECIAL NOTE ON CARTRIDGE OVERALL LENGTH “COL”
It is important to note that the SAAMI “COL” values are for the firearms and ammunition manufacturers industry and must
be seen as a guideline only.
The individual reloader is free to adjust this dimension to suit their particular firearm-component-weapon combination.
This parameter is determined by various dimensions such as 1) magazine length (space), 2) freebore-lead dimensions of
the barrel, 3) ogive or profile of the projectile and 4) position of cannelure or crimp groove.


What Hornady 55gr bullet are you using? If it's their FMJ, so-so groups may be all you can get. These are probably one of the best FMJ bullets available, but they are still rather poor when it comes to pin point accuracy. That's why they are so cheap. If you are looking for Sub-MOA groups you might consider a better bullet, something like the V-Max, Ballistic Tip or Sierra.

As for the crimp, read this from Sierra.

Neck Tension

When we stop to consider the vigorous (read, downright violent) chambering cycle a loaded round endures in a Service Rifle, it becomes pretty clear it suffers abuse that would never happen in a bolt-action. This is simply the nature of the beast. It needs to be dealt with since there is no way around it.

There are two distinctly different forces that need to be considered: those that force the bullet deeper into the case, and those that pull it out of the case. When the round is stripped from the magazine and launched up the feed ramp, any resistance encountered by the bullet risks having it set back deeper into the case. Due to the abrupt stop the cartridge makes when the shoulder slams to a halt against the chamber, inertia dictates that the bullet will continue to move forward. This is exactly the same principle a kinetic bullet puller operates on, and it works within a chamber as well. Some years ago, we decided to examine this phenomenon more closely. During tests here at Sierra’s range, we chambered a variety of factory Match ammunition in an AR-15 rifle. This ammunition was from one of the most popular brands in use today, loaded with Sierra’s 69 grain MatchKing bullet. To conduct the test, we chambered individual rounds by inserting them into the magazines and manually releasing the bolt. We then repeated the tests by loading two rounds into the magazine, chambering and firing the first, and then extracting and measuring the second round. This eliminated any potential variation caused by the difference between a bolt that had been released from an open position (first round in the magazine) and those subsequent rounds that were chambered by the normal semi-automatic operation of the rifle. Measuring the rounds before chambering and then re-measuring after they were carefully extracted resulted in an average increase of three thousandths (0.003") of forward bullet movement. Some individual rounds showed up to seven thousandths (0.007") movement. Please bear in mind that these results were with factory ammunition, normally having a higher bullet pull than handloaded ammunition.

To counteract this tendency, the semi-auto shooter is left with basically two options: applying a crimp or increasing neck tension.


Link to entire article.

http://www.exteriorballistics.com/re...sgunreload.cfm

[hounddawg]

great info guys thanks. Darn the bad luck, guess I am just going to have to force myself to make another trip to the range this weekend. I am going do try another workup seated to the cannalure and using a light crimp. A guy has do do what a guy has to do right

[DiscoRacing]

I hate having to make extra trips to the range...dont like making excuses to go to the range... now I leave out all the excuses and just make the extra trips to the range...after seeking professional help from the doc...we found that it helps me to just leave out the word..extra...and call them..much needed.. trips to the range.

The preceeding text may have been BS..only published for amusement of some sort..

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