Hi Guys,

Yesterday I went to the range and brought the Prairie Hawk 8mm with me. It was a rainy and breeze day, so not the best weather to achieve the best groups, but the weather will always be out of our control.

During the past few months, we’ve been sorting out some issues that kept the rifle underperforming (accuracy wise) compared to the original specs.

Some of the variables that we have worked included:

1) The regulator malfunctioning- it was rebuilt.
2) Slugs-tried different slugs from different molds and the results were mixed. (more later)
3) The rifle- cleaned the barrel, oiled every possible part without taking it apart.
4) Trying different power settings on the rifle. For the moment I decided to keep it in the hotter setting and find the correct slug for this setting.
5) My technique

At some point, going to the range with the PH became a new experiment to test expecting a possible solution to the accuracy issue. Just to be clear, I have enjoyed every moment of the process and I have received support from Gary and Jerry all the way along this process.

Finally after having some slugs discussions with Jerry, I did asked him to measure the diameter of the sized twin tail slug and to compare it with the unsized diameter. After doing this comparison we realized that we have been using the wrong sizing die for this particular slug. In all my previous orders, I’ve always asked for the 8mm slugs to be sized. After realizing this new finding, I proceeded to place a new 8mm slugs order and leave them unsized.

The following are some pictures of groups shot at 55 yards using the 8mm Twin Tail unsized slugs. These next two pictures were the best groups of the session:







This next picture is a perfect example of something that kept happening again and again. At least 6 to 8 groups had this same pattern. (Two shots touching and a flier, close but not touching the other two shots)



At this point I do believe that those fliers were caused by a technique issue. There is still room for improvement, because now that we have found the correct slug, it's time for me to go to the range and put some hours improving my technique.

Jerry, I did ran out of slugs so please check your PM.

I do like to give my special thanks, again, to Gary and Jerry for their support and advice during all this process.

Julio

Hello Julio,

That's great. Thanks for the post and pics.

To quote an old airgunsmith blessing (that I just made up) ... .... "May all your fliers, land within a half an inch of your group!" hahahahah.

I'm glad we've got the gremlin on the run. It's been maddening to find what was wrong. I also put a couple of different barrels on the gun during development. Different rifling twist rates. Made quite a few bullet cherries and molds. It would have been impossible NOT to get something mixed up. I had, and posted, so many excellent results with the gun. But then, there was the documentation to determine which this and that had produced the results. I try to record much. Try to mark the targets with reliable information. But - things slip by without being recorded. Or - they are recorded and misunderstood later.

But - we've proven that if you try enough ... ... you will succeed.

Best,
Gary

Good post Julio, I enjoyed the read. Sounds like you have been having a great time getting everything sorted out. I have always liked the 8mm bullet, it always seemed a natural to me for big bore airguns. The diameter is perfect for heavy streamline bullets that produce a good coeffecient and carry good energy down range. Glad to know you are getting her dialed in.
Joe

Hi Joe,

This slug will really pack a punch. You recall that switchblade target that I used to have. This slug would punch those monster plate steel panels down with authority.

I've wanted to make a set-up that would be a pure hunting rifle to shoot this. Well, actually ... I'm making that 308. And, an early version of this slug (for the very fast twist prototype barrel) was smaller. Hummmmm .... might size down to try in that. If the breech port is long enough.

Are you feeding my deer Joe? I don't want to drive all that way for some skinny deer. hahaha. Toss a handfull of that "horn grower mix" into the bucket too. heheheh.

Gary

Excellent! I'm glad we'v narrowed things down Julio!

I'm going to the airport in a few minutes to pick up Timmy. We'll get that PM taken care of asap.

I hear you Gary, actually I thought about you the other morning when I came in from work. There were 5 bucks standing just out behind the house when I go out of the truck. Two of the five had decent racks, one was a nice 9 pointer with about 16 to 17 inch spread and a nice high rack. The other looked like a 8 pointer about 14-15 inches wide. I have been seeing them pretty regular from a distance but they were close enough to take with an airgun that morning. Wiley will be your competition, he is straining at the bit for anything that even looks like a deer.
Get that rifle ready to test and I'll skin out the first one for you.

A deer with honest to goodness horns??? Holly COW!!! I mean deer!!!

Wow .... I feel my trigger finger itching ... heheh.

Good stuff. I've got a bullet all polished up. I'll keep it in my shirt pocket, for safety.

Looking forward to it.

I have your parts now. Can't wait to get that all finished up now too. Doctor's appt. in the morning. I sincerely hope they find something on those MRIs that can be fixed. This mystery misery is about wringing me dry. We'll see.

I will very much enjoy a visit, a hunt, and some shared time in your shop ... if you'll have me. Sounds very neighborly of you.

Gary

Hey Julio....

In the past few months the Prairie Hawk have been your nightmare. I now that for sure.

You shooted, asked people, adjusted it in conjuction with the selection of ammunition you tested again, again and again.... and you know my Friend, You have not just have a more accurate beautiful rifle, now, You gain the most important with your air rifle EXPERIENCE. Now I know you have a better understanding of what you have in your hands and YOUR LADY requirements for be a nice accurate shooter!!!

CONGRATS PARTNER... AND WELCOME TO THE REAL WORLD OF AIRGUNS!!!

But now..... Let's go to serious bussiness as I asked you at the range. ARE YOU READY FOR A COMPETITION???

The BIG BORE vs SMALL BORE
The Beauty 'Prairie Hawk 8mm' vs The korean Killer 'THE SUMATRA .22'

Challenge Place: LUQUIS RANGE at Caguas, Puerto Rico

The day and rules will be in discussion between us when you can buddy and then will be posted here!!!



/ Congrats Again, Julio

GERALD / PUERTO RICO



Edited 1 time(s). Last edit at 07/25/2011 02:21PM by kp4att.

Hello Gerald,

We need to agree on a date, for the moment I’m out of 8mm amo. I need to order some slugs from Surefire Casting. As soon as I receive the slugs we can arrange for a date and sort all the match details.

It was nice to see you and share some time with you at the range this last Friday.

Julio

Julio, I know you finish all the 8mm slugs last friday

/ Make sure you order enough slugs for that day (500) / It will be better than our first competition.

This time we will have more time to shoot, no rifles to set.

FOR THAT DAY LET'S GO TO DO SOMETHING DIFFERENT AS WE DID THE FIRST TIME.




/GERALD



Edited 1 time(s). Last edit at 07/29/2011 12:40PM by kp4att.

Gerald,

Sounds good! We'll discuss the details and then we will post the match details here in the forum.

Julio

Hi Julio,

I'm glad to see you guys have some good times at the range. Wish I were there.

You will never really have an even "competition", unless you are shooting in the same power range. It is a different challange, to project a lot of power and bullet mass onto a long range target.

Looks like Gerald has a very nice rig there. I'll bet he knows how to use it too.

Have fun. But - include in your competition, knocking down some bricks at 100 yards ... just for me.

best,
Gary